3. Keihin Parts for 1977-83 NC50, NA50, NX50, NU50, NCZ50

April 3, 2021

== carb ID# ============  M O P E D S  ===========
6. PA 08B-A  1977-78 Honda NC50 Express xxx    30 mph TS
6. PA 08B-B  1977-79 Honda NC50, NA50  xxxx    30 mph TS
6. PA 08C-A  1978-79 Honda NC50, NA50  xxxx    30 mph TS
6. PA 08E-A  1980-80 Honda NC50 Express xxx    30 mph TS
6. PA 08E-B  1980-80 Honda NC50 Express xxx    30 mph TS
6. PA 08D-A  1980-80 Honda NA50 Express II x   30 mph TS
7. PA 12A-A  1981-81 Honda NCZ50 Moto Compo
7. PA 15A-A  1981-81 Honda NC50 Express xxx    30 mph TS
7. PA 16A-A  1981-81 Honda NA50 Express II  x   30 mph TS
7. PA 13B-A  1981-82 Honda NX50 Express SR x   30 mph TS
7. PA 13B-B  1982-83 Honda NC50 Express xxx     30 mph TS
7. PA 13E-A  1982-83 Honda NU50 Urban Express 30 mph TS
7. PA 25A-A  1982-83 Honda NC50AA, NU50AA      25 mph TS

 

 

 

 

 

6. Keihin
size     carb  model code  year 00 frame number range  000  model
∅12 PA08B-A or B #147 1977 NC50-1139281 to 0000000 NC50 Express (US)    30 mph
∅12 PA08B-A or B #147 1978 NC50-2000013 to 0000000 NC50 Express (US)    30 mph
∅12 PA08E-A or B #147 1979 NC50-2100011 to 0000000 NC50 Express (US)    30 mph
∅12 PA08E-A or B #147 1980 NC50-2200005 to 0000000 NC50 Express (US)    30 mph
∅12 PA08B-B    on #163 1979 AB01-5000001 to 0000000 NA50 Express II (US) 30 mph
∅12 PA08D-A    on #163 1980 AB01-5200001 to 0000000 NA50 Express II (US) 30 mph

 

1977 Honda NC50 Express

1978 Honda NC50 Express

’79 NC50 Express

 

 

 

 

 

 

 

 

 

1980 Honda NC50 Express

1980 Honda NA50 Express II

 

 

 

 

 

 

 

 

 

 

 

#0  16100-147-675
Keihin PA08B-A

#0 16100-147-676
Keihin PA08B-B

#0 16100-147-711
Keihin PA08E-A

 

 

 

 

 

 

 

 

 

#0 16100-147-712
Keihin PA08E-B

16100-163-771
Keihin PA08D-A

 

 

 

 

 

 

 

 

Flange Mount: 38 mm hole spacing. 2 x 20 (24 od) intake o-ring.

Honda Express carburetor versions, showing things that are different.

Honda Express carburetor versions

Cable choke: This carburetor has a throttle cable and a choke cable coming straight up and looping around. It has no vent hoses, vacuum hoses, or oil lines going into it. The oil injection goes into the intake manifold. The float reservoir vent is just a small tube slanting downward.

As with most Honda carburetors, fuel is never allowed to spill onto the engine or anything else. Instead an overflow tube inside the float chamber allows any overflow fuel to flow out and down the drain hose and onto the ground below the engine.  

The 1977-79 Honda NC50 and NA50 each had two carburetor versions, PA08B-A and PA08B-B. Regardless of the year, or the VIN number, they could have either version. So the customer had to look at the model number stamped into the carburetor, and tell the Honda dealer that number, to get certain parts correct. 

Oil injection hose location: The 1977-79 Honda Express had the oil hose going into the intake manifold, not the carburetor. The 1980 and later models had the oil injection hose going into the carburetor at the throttle slide area. There must have been some benefit, like maybe throttle slide lubrication.

16010-143-620
has a, c, d, e, f, g
for PA08 BA

16010-143-305
a, c, d, e, f, g, h, i 
for PA08 BA

16010-147-004
has b, c, f, g
for PA08 BB, EB

16010-147-711
has b, c, d, f, g
08 BB EB DA EA

16010-147-505
has b, c, d, f, g, i
08 BB EB DA EA

 

 

 

 

 

 

 

 

 

    quantity
o# ⇓⇓⇓⇓⇓  Keihin PA(a)08BA (b)08BB (c)08EA (d)08EB (e)08DA 
o# abcde price  Honda part#x  description xxx specs
10 1oooo  N/A 16100-147-673 
10 1oooo  N/A 16100-147-675 carburetor 77-79 NC50 PA 08B-A
10 o1ooo  N/A 16100-147-676 carb 77-79 NC50 NA50 PA 08B-B
10 oo1o0  N/A 16100-147-711 carburetor  1980 NC50 PA 08E-A
10 oo01o  N/A 16100-147-712 carburetor  1980 NC50 PA 08E-B
10 oooo1  N/A 16100-163-771 carburetor  1980 NA50 PA 08D-A
o1 10ooo $26 16010-143-620 gasket solo-set   1a o c d e f g
o1 10ooo $28 16010-143-305 gasket multi-set  1a o c d e f g h i
o1 01o1o $23 16010-147-004 gasket solo-set   oo b c o o f g
o1 o1111 $23 16010-147-711 gasket solo-set   oo b c d o f g
o1 o1111 $24 16010-147-505 gasket multi-set oo b c d o f g o i
1a 100o0 $$3 00000-000-000 top rubber washer 10 x 18 x 1
1b o1111 $$8 00000-000-000 top rubber washer 13 x 16.5 x 1
1c 11111 $$2 00000-000-000 intake o-ring 2 x 20 (24 od) 
1d 1o1o1 0$2 16176-551-004 jet or screw o-ring 1 x 3 (5 od)
1e 1o0oo $13 16197-063-004 jet support pad disk Ø7.5 x 1.8
1f  11111 $18 00000-000-000 float bowl gasket  Ø1.5 NC50-type
1g 11111 $$2 00000-000-000 drain plug o-ring 1.5 x 4 (7 od)
o2 1oo1o $21 16011-881-741 float needle valve  stirrup
o2 1oo1o $36 16011-881-741 float needle genuine stirrup
o2 o11o1 $22 16155-883-005 float needle valve regular
o3 1o1o0  N/A 16012-147-004 needle set 3a 3b 3c 3d 08BA EA
o3 ooooo $22 16012-130-640 needle set 3a 3b 3c 3d PA 03A-A
o3 ooooo $22 16012-165-014 needle set 3a 3b 3c 3d PA 03B-A
o3 o1o11 $15 16012-147-014 needle set 3a 3b 3c 08BB EB DA
3a 11111 0$5 16156-044-004 jet needle w-clip
3b 11111 0$2 16157-044-004 jet needle e-clip 1.5 for Ø2.0 needle
3c 11111 $10 00000-000-000 jet needle Ø2.0 D348 thick 08B-A,
3c 11111 $10 00000-000-000 PA 08B-B, 03A-A, 00A, 01A
3c ooooo $10 00000-000-000 jet needle Ø2.0 D117 thin 03B-A,
3c ooooo $10 00000-000-000 PA 03C-A, 03D-A, 03H-B, 03M-A, etc
3d 1o1oo  N/A 00000-000-000 needle jet (emulsion tube) 08BA 08EA
3d o1o11  N/A 00000-000-000 needle jet & jet fixed 08BB 08EB 08DA
3d ooooo $10 00000-000-000 needle jet (emulsion tube) PA 03A-A
3d ooooo $10 00000-000-000 needle jet (emulsion tube) PA 03B-A
o4 1oo1o  N/A 16013-143-620
o4 1oo1o  $46 16013-099-691 float set 4a oo 4c 4d black stirrup
o4 o11o1 $28 16013-147-004 float set oo 4b 4c 4d white regular
4a 1oo1o  N/A 00000-000-000 float bare, solid black foam stirrup
4b o11o1 $21 00000-000-000 float bare hollow white plastic regular
4c 11111 $$4 00000-000-000 hinge pin substitute Ø2 x 18.5
4d 11111 $$3 0-93600-04006 hinge screw M4x6 sunk phillips

1977-79 NC50 idle adjustment screws
7a idle speed screw, tighter is faster
7c idle air mix screw, tighter is richer

o5 1oooo $23 16014-143-620 top set substitute 5a 1a M20-1.0
o5 o1111 $22 16014-147-004 top set substitute 5a 1b M18-1.0
o6 1oooo  N/A 16015-147-004 chamber set A 6a oo 6c 1e 1f 1g for jet pad
o6 o1111  N/A 16015-147-014 chamber set B oo 6b 6c oo 1f 1g for no pad
6a 1oo0o  N/A 16015-147-004 float bowl A shallow with pad holder
6b o1111  N/A 16015-147-014 float bowl B shallow, no jet pad holder
6c 11111 $16 00000-000-000 float drain screw M6x20 special
o7 11o1o $15 16016-143-620 screw set 7a b c d idle air
o7 oo101  N/A 16016-147-711 screw set 7a b o d e f g idle fuel
7a 11111 $$4 00000-000-000 idle speed screw M4x19 special
7b 11111 $$2 00000-000-000 idle speed screw spring Ø5.6 x 10
7c 11o1o $$9 00000-000-000 idle air screw M6-0.75 thick tip
7d 11111 $$7 00000-000-000 idle air or fuel spring Ø4.8 x 9
7e oo1o1 $12 00000-000-000 idle fuel screw M6-0.75 thin tip
7f  oo1o1 $$7 00000-000-000 idle fuel screw washer 3.1 x 5.0 x 0.5
7g oo1o1 0$2 16176-551-004 idle fuel screw o-ring 1 x 3 (5 od)

1980-83 NC50 idle adjustment screws
7a idle speed screw, tighter is faster 
7e idle fuel mix screw, tighter is leaner

o8 11111 $38 16022-143-620 valve set 8a, 8b
8a 11111 $22 00000-000-000 throttle slide Ø13 #15A
8b 11111 $12 00000-000-000 throttle spring original Ø9.5 x 42
8b 11111 $$7 00000-000-000 throttle spring substitute shorter, stiffer
o9 11111 $25 16046-147-004 choke set substitute 9a 9b 9c
9a 11111 $15 00000-000-000 choke top substitute M12-1.0
9b 11111 $$4 00000-000-000 choke spring substitute
9c 11111 $12 00000-000-000 choke slide substitute

11 11111 $2.00 16118-166-004 rubber boot substitute Dellorto
12 22222 $1.00   93500-04012 bowl screw M4x12 pan phillips
13 22222 $0.20   94111-04000 lock washer M4 split
14 11111 $1.00 95001 – 35003 hose substitute 1/8 x ¼ 3.1 x 6.3


15 11111  N/A 95002 – 02070 drain hose clamp B7 (for 7 not 6.3)
16 10o0o  N/A 99201.081.0780 push-in jet 78 08BA
16 10o0o $23 substitute jet, #70 drilled to 78 08BA
16 01111  N/A fixed needle jet & jet pressed in 08BB EA EB DA
this jet is 0.78mm 0.0307″, cleaned with a #69 drill 0.0292″     

00 22222 $1.00 mount bolt, nut and washer M6 x 20

 

Float: The white float with non-stirrip needle for PA08B-B and the black float with stirrup type needle for PA08B-A do not interchange. The white float is too “tight” on the PA08B-A. Something restricts its movement. The black float is too “loose” on the PA08B-B. It moves a lot before moving the needle.

Main Jet: On PA08BB, EA, EB and DA versions the main jet is a tamper-proof tight press-fit type, in the center. The jet cannot be removed, and cannot be replaced. It is 0.78 mm – 0.0307″, and can be cleaned perfectly with a #69 drill 0.0292″.    

On a PA08BA the main jet presses or slides in and out, and is supported by a rubber disk. If the disk is missing, the jet can slide downward, allowing fuel to get past the jet o-ring, causing a rich fuel mixture.

Idle Hole Cleaning: Near the engine side of the carb body is a brass tube that dips down into the liquid gasoline. That tube, about 1.5 mm (0.060″) inner diameter and 20mm long, leads to the idle or pilot jet, which is about 0.30 mm (0.012″). The idle jet gets clogged from sitting, then the engine will run but won’t idle. Nothing but a very thin (0.010″) steel guitar string will clean it out. See below about jet drills and cleaning tiny jets. Ultrasonic parts cleaners, carb spray, carb dip, and compressed air are not usually effective. Another way to clean out the idle jet is to 1) place a drill bit that fills the hole (so it does not get crushed), 2) clamp it with a small vise grips, 3) rotate back and forth while pulling, 4) when it comes out, the actual hole is easy to see and clean, 5) press it back in the same way it came out.

Strong solvent is needed to dissolve varnish or tar residue left from years of sitting. Carburetor spray, parts dip, or acetone all help clean out the tar, sometimes with a lot of scraping, brushing or rubbing. Always remember to remove all rubber things first, to not let the rubber touch the solvent. Strong solvents will swell soft rubber, deforming it. Never soak the whole carburetor in strong solvent. In this way, Shaun (at Royal Cyclery and later at Myrons Mopeds) has successfully cleaned out over 100 Honda Express carburetors, without ever replacing any of the rubber gaskets. Part of the reason was they were only sold at Honda dealers, but nonetheless, they are not needed in a normal service or clean-out.

Keihin PA08C-A: This is approximately for a 1979-80 NC50, or maybe NA50. It is identical to a PA08B-B. It has the same white float, non-stirrup float needle, fixed jet, 18mm top threads, and same gaskets. The idle mixture screw type is unknown. No photo available. 

 

7. Keihin
size  carb  model code  years       models
∅12 PA12A-A on #GC6 1981-81 Honda NCZ50 Moto Compo
∅12 PA15A-A on #190 1981-81 Honda NC50 Express (US) xxxxx xxxx 30 mph
∅12 PA16A-A on #193 1981-81 Honda NA50 Express II (US) xxxx xxx  30 mph
∅12 PA13B-A on #187 1981-82 Honda NX50 Express SR (US) xxxx xx  30 mph
∅12 PA13B-B on #GA6 1982-83 Honda NC50 Express (US) xxxxx xoxx 30 mph
∅12 PA13E-A on #GC1 1982-83 Honda NU50 Urban Express (US) xxxx 30 mph
∅12 PA13E-A on #GC1 1982-83 Honda NU50M Urb. Expr. Deluxe (US)  30 mph
∅11 PA25A-A on #GA6 1982-83 Honda NC50AA Express (Iowa) xxxxxx  25 mph
∅11 PA?????   on #GC1 1982-83 Honda NU50AA Urban Express (Iowa)   25 mph
∅10? PA25A-A on#GC1 1982-83 Honda NU50MA Urb. Ex. Deluxe (Iowa) 25 mph

 

1981 NC50 Express

1981 NA50 Express II

1981 NX50 Express SR

1982 NU50 Urban Express

 

 

 

 

 

 

 

 

#0   16100-GC6-003  Keihin PA12A-A 

16010-187-003 gasket set

 

 

 

 

 

 

 

 

#0  16100-190-672
Keihin PA15A-A

#0  16100-193-672
Keihin PA16A-A

#0  16100-187-673
Keihin PA13B-A

 

 

 

 

 

 

 

 

#0 16100-GA6-671
Keihin PA13B-B

#0 16100-???-???
Keihin PA25A-A

#0  16100-GC1-671
Keihin PA13E-A

 

 

 

 

 

 

 

 

Flange Mount: 38 mm hole spacing, 2 x 20 (24 od) o-ring on NC50, NA50 (PA15A-A, PA16A-A, PA13B-B)
Flange Mount: 32 mm stud spacing, 2 x 18 (22 od) o-ring on NX50, NU50, NU50M (PA13B-A, PA13E-A)
Flange Mount: 36 mm hole spacing, 2 x 20 (24 od) o-ring on NC50I, (PA25A-A)

Vacuum-operated automatic choke: These carburetors feature a screw-in main jet, and a built-in vacuum-operated (not electric) automatic choke. When the temperature switch on the head is cold, it allows the engine vacuum to raise the choke plunger up, which opens a new fuel passage, to enrich the mixture during cold starting. As the engine warms up, it closes the vacuum, allowing the thin spring to pull it back down, for normal running. The more precise term for this is “automatic vacuum operated cold start fuel mixture enrichment device”. The 1981-83 automatic choke device itself is not replaceable.

The vacuum source hose has a check ball valve that only allows air flow into the carburetor venturi, and not back out. It needs this even though there is reed valve, because there is still some residual reverse flow caused by the forward and reverse motion of the piston.

The vacuum choke that came out in 1981 did not last long. After 1983, 50cc on-road Honda’s had electric chokes, because they were electric-start scooters with 12 volt batteries. 

Identical twins: The PA16A-A looks identical to the PA15A-A. It is on the 1981 Honda NA50 Express II, the final year of that USA-only model. They both have 38 mm flange hole spacing, #75 screw-in jet, 20 mm intake o-ring and the non-stirrup type B float needle. The only difference is the top cable curved pipe. On a PA15A-A it is permanently attached to the screw-on top cap with a swivel joint, while on a PA16A-A the curved cable pipe is detachable.

Intake studs: After 1981 these carbs had studs instead of threaded holes in the mounting flange, except for PA25A-A. PA13B-A and PA13E-A studs are spaced 32 mm with a 18mm intake o-ring. PA13B-B studs are spaced 38 mm, with a intake o-ring 20 mm. 

Iowa carb: The PA25A-A is like a PA13B-A, with M18-1.0 top cap threads, 13.0 mm slide, vacuum-operated automatic choke, choke jet in float bowl, tall 2.5 x 1.5 float bowl gasket, intake o-ring 20 mm, 38mm mount spacing, non-stirrup type float and float needle, screw-in main jet size 75. The only noticeable difference is the absence of studs.

Iowa cylinder: The exhaust port is restricted. Here left is 49-state, right is Iowa.

Keihin PA12A-A: This carb from a NCZ-50 has a cable choke like the ’77-79 NC50 carbs. But it has a different part number, 16046-GC6-003 instead of 16046-147-004. Despite that, the NC50 replacement cable choke top and choke pieces fit the NCZ50.  

 

#1 16010-190-004
for 15A 16A 13BB 25A

#1 16010-187-003
for 12A 13BA 13EA

#1  16010-GF8-305 for
for PA 13BA 13EA

 

 

 

 

 

 

 

 

 

PA 15AA 16AA 13BA 13BB 13EA

      quantity
o# ⇓⇓⇓⇓⇓⇓  PA (a)15AA (b)16AA (c)13BA (d)13BB (e)25AA (f)13EA
o# abcdef price  Honda part#x  description xxx specs
00 1o0000  N/A 16100-190-672 carburetor ’81-81 NC50 PA15A-A
00 o10000  N/A 16100-193-672 carburetor ’81-81 NA50 PA16A-A
00 o01000  N/A 16100-187-673 carburetor ’81-82 NX50 PA13B-A
00 o00100  N/A 16100-GA6-671 carburetor ’82-83 NC50 PA13B-B
00 o00010  N/A 16100-GA6-671 carburetor ’82-83 NC50AA PA25A-A
00 o00001  N/A 16100-GC1-671 carburetor ’82-83 NU50 PA13E-A
01 001001 $24 16010-187-003 gasket solo-set   1b o d g h k
01 110110 $24 16010-190-004 gasket solo-set   1b c d g o k
01 001001 $25 16010-GF8-305 gasket multi-set 1b o d g h k t u
1b 111111 $$8 00000-000-000 top rubber washer 13 x 16.5 x 1
1c 110110 $$2 00000-000-000 intake o-ring 2 x 20 (24 od) 
1d 111111 0$2 16176-551-004 idle fuel screw o-ring 1 x 3 (5 od)
1g 111111 $$2 00000-000-000 drain plug o-ring 1.5 x 4 (7 od)
1h 001001 $$2 00000-000-000 intake o-ring 2 x 18 (22 od)
1k 111111 $22 00000-000-000 float bowl gasket 2.5 tall by 1.5 wide
02 0010?0  N/A 16012-187-671 needle set ’81 2a 2b 2c 2d
02 001000  N/A 16012-187-731 needle set ’82 2a 2b 2c 2d
02 1100?0  N/A 16012-193-671 needle set 2a 2b 2c 2d
02 0001?1  N/A 16012-GA6-671 needle set 2a 2b 2c oo 2e
02 0000?1  N/A 16012-GC1-671 needle set 2a 2b 2c oo 2f
2a 111111 0$5 16156-044-004 jet needle w-clip
2b 111111 0$2 16157-044-004 jet needle e-clip for 1.5 clip groove
03 111111 $28 16013-147-004 float set white 3a 3b 3c
3a 111111 $21 00000-000-000 float bare white plastic regular
3b 111111 $$4 00000-000-000 hinge pin substitute Ø2 x 18.5
3c 111111 $$3 0-93600-04006 hinge screw M4x6 sunk phillips
04 1o0000  N/A 16014-190-014 top set NC50 fixed cable pipe M18-1.0
04 o10000 $24 16014-147-014 top set NA50 detachable pipe M18-1.0
04 o01110  N/A 16014-187-013 top set NX50, 82-83 NC50 M18-1.0
04 o00001  N/A 16014-GB2-003
04 o00001  N/A 16014-GB0-831 
04 o00001  N/A 16014-098-980 top set NU50 fixed cable pipe M18-1.0
05 110000  N/A 16015-191-034 chamber set deep bowl with choke jet
05 001000  N/A 16015-187-671 chamber set deep bowl with choke jet
05 0001?0  N/A 16015-GA6-671 chamber set deep bowl with choke jet
05 0000?1  N/A 16015-187-043 chamber set deep bowl with choke jet
06 000111 $32 16016-191-004 idle fuel screw set 6a 6b 6f 1d
06 111000 $32 16016-187-003 idle fuel screw set 6a 6b 6f 1d
6e 111000 $12 00000-000-000 idle fuel mixture screw M6-0.75 special
6b 111111 $$7 00000-000-000 idle fuel mix screw spring Ø5 x 9
6f  111111 $$7 00000-000-000 idle fuel mix screw washer 3.1×5.0x0.5
07 111111 $0016028-187-003
07 111111 $15 16028-GC8-004 idle speed screw and spring 7a 7b
7a 111111 $$4 00000-000-000 idle speed screw M4x19 special
7b 111111 $$2 00000-000-000 idle speed screw spring Ø5.5×10
08 110000 $38 16022-143-620 throttle slide & spring
08 001011  N/A 16022-187-731 throttle slide & spring
08 000101  N/A 16022-191-004 throttle slide & spring
8a 11?? 1? $22 00000-000-000 throttle slide Ø13 #15A
8b 11?? 1? $12 00000-000-000 throttle slide spring Ø9.5 x 42

NC50 idle fuel screw
top: original 
bottom: replacement

10 100000  N/A 16118-086-004
10 100000  N/A 16118-166-004 cable rubber boot
10 101110  N/A 16118-187-003 cable rubber boot
10 000001  N/A 16118-GB4-003 cable rubber boot
11 111111 $22 16155-883-005 float needle valve KL 18-4608
12 110110  N/A 16199-435-771 overflow hose 3.0 x 6.5
12 001001  N/A 16199-187-003 
12 001001  N/A 16198-HC0-405 overflow hose 3.0 x 6.5
13 001000  N/A 16608-187-000 control hose with check ball 5 x 10
13 110000  N/A 16608-193-670 control hose with check ball 5 x 10
13 000110  N/A 16608-GA6-670 control hose with check ball 5 x 8
13 000001  N/A 16608-GC1-000 control hose with check ball 5 x 8
14 222222 0$1 93892-04012-08 screw & washer M4x12 pan phillips
15 111111  N/A 95002 – 02070   hose clamp B7 vacuum source hose
16 111000  N/A 95002 – 02100   hose clamp B10 for control hose
16 000111  N/A 95002 – 02080   hose clamp B8 for control hose
17 111111  N/A 95002 – 02650   hose clamp B6.5 for overflow hose
18 111111  N/A 95005 – 35001   vacuum (source) hose 3.5 x 7 x 130
19 oo0010 $$7 99101-187-0700 screw-in jet #70 M6-0.75 PAMOA PA25A ? 78-80 Indian, 82-83 NC50I
19 110100 0$7 99101-187-0750 screw-in jet #75 M6-0.75 PA15A 16A 13BB 81-83 NC50, 81 NA50
19 oo1000 0$7 99101-187-0780 screw-in jet #78 M6-0.75 PA13BA 81-82 NX50
19 oo0001 0$7 99101-187-0850 screw-in jet #85 M6-0.75 PA13EA 82-83 NU50

 

 

Float Valve Seat: On these carburetors the float seat (the cup that the float needle valve slides in) is carved into the actual carburetor body, and is not replaceable. Polish it with a spinning Q-tip and polish, such as Turtle Wax. 

Choke jet: On all of these NC50-type carbs, both shallow and deep-float-bowl versions, there is a choke jet, pressed into a corner of the float bowl. When it gets clogged the engine will only start easily when it is warm.

Verify all jets and fuel or air passageways are open, using wires and or visually with carb spray (wear goggles).

Cable Differences: You can tell what year range a Honda Express is from a distance. A 1977 to 1980 has two cables, a throttle and a choke cable coming straight up from the carburetor.  A 1981 has just a throttle cable coming straight up, but also a vacuum hose for the choke and a float vent hose.  A 1982 to 1983 has a black plastic curved elbow on top, that redirects the throttle cable forward and down, a vacuum hose for the choke, and a vent hose. A 1982-83 also has a different frame, a low headlight, and a two speed transmission.

The Honda Express throttle cable curves rearward and loops downward to get below the carburetor, and then goes forward into the frame tube. The loop design adds friction, but it makes a good clean step-thru frame without any cables or wires hanging out.  

1982-83 NC50 hoses

Comparison of PA MOA-A, PA 08B-B, PA 08B-A, and PA 15A-A

 

 

 

 

 

 

 

 

 

Keihin idle mixture screw channels
Left PA08B-B with idle air screw
Right PA15A-A with idle fuel screw

 

 

You can tell the difference between a carb with an idle air mixture screw, and a carb with an idle fuel mixture screw, by the shape of the casting at the top of the float chamber.

 

 

 

 

 

 

 

 

Mikuni Carburetors

October 19, 2016

Contents:
1 a. for 1979-81 Yamaha QT50, VM12-SC-3L5 round float
   b. for 1982-87 Yamaha QT50, VM12-SC-4L4 round float
   c. for 1983-02 Yamaha PW50, VM12-SC-4X4 round float
   d. for 2003-06 Yamaha PW50, VM12-SC-5PG round float
2 a. for 1983-90 Trac (Daelim),  VM13-SC-R4  round float
   b. for 1980-84 Indian AMI50,  VM10-SC-H9  round float
3.    for 1976-80 Angel (TYM),  VM10-24 square twin float 
4.    Other Carbs like Mikuni
5.    Mikuni Jets
6.    Info
7.    Tillotson Carburetor on 1978 Indian AMI-50

These are the baby Mikuni’s, the smallest of the small, 10 to 13mm for limited 50cc engines. See Info below.  

1. Mikuni VM12SC on Yamaha QT50 and PW50

This is a 12mm carburetor (12mm venturi diameter) with a 18mm clamp diameter.

It is not like any common Mikuni for a limited 50cc, like a moped or a kids off road. Apparently, Mikuni made carbs according to to each big manufacturer’s design. So Kawasaki KDX50, Suzuki JR50 have baby Mikuni carbs but with different designs than Yamaha PW50 and QT50. 

VM12SC versions: The first version was 3L5 on 1979-81 QT50. It had an idle air screw just to the left of the idle speed screw. After 1981, on versions 4L4, 4X4, 5PG the air screw was to the right of the idle speed screw. The off road 4X4 and 5PG versions were mostly the same except the cables exited at 90 degrees, with metal curved pipes, instead of straight up.

1979-81 Yamaha QT50
3L5-00 with #75 jet
3L5-01 with #70 jet

1982-87 Yamaha QT50
4L4-00 with #70 jet

1983-02 Yamaha PW50 4X4-00
2003-06 Yamaha PW50 5PG-00

 

 

 

 

 

 

 

 

 

 

Mikuni 3L5, 4L4, 4X4, 5PG

Combined Parts List  A= 3L5 on ’79-81 QT50,  B= 4L4 on ’82-87 QT50
Combined Parts List  C= 4X4 on ’83-02 PW50, D= 5PG on ’03-06 PW50
#  quantities
01 A B C D   Yamaha # xxx price    description
01 1 0 0 0  3L5-14101-01    N/A  carburetor 70 jet 79-81 QT50
01 0 1 0 0  4L4-14101-00    N/A  carburetor 70 jet 82-87 QT50
01 0 0 1 0  4X4-14101-00    N/A  carburetor 70 jet 83-02 PW50
01 0 0 0 1  5PG-14101-00    N/A  carburetor 70 jet 03-06 PW50
02 1 1 1 1  3L5-14181-07    N/A  float bowl
03 1 1 1 1  3L5-14184-00    N/A  float bowl gasket
04 1 1 1 1  620-14231-14 $8.00 main jet 70 M5-0.75 large round
05 1 1 0 0  3L7-14141-10    N/A  needle jet E0 Ø2.05
05 0 0 1 1  3L7-14141-12    N/A  needle jet
06 1 1 1 1  3L5-14142-40 $0.00 idle jet 40 M4-0.7 thread
07 4 4 4 4  98580-04014  $0.70 float bowl screw M4 x 14 phillips
08 1 1 1 1  3L5-14198 00    N/A  top gasket
09 1 1 0 0  3L5-14158-00    N/A  carb top cap
10 2 2 0 0  12G-14106-00 $5.00 cable adjuster-stop M6-0.75 
11 2 2 1 1  802-14161-00 $2.50 adjuster lock nut M6-0.75 x 3 hex9
12 2 2 0 0  8A7-14169-10 $2.00 cable rubber cap
13 1 1 1 1  3L6-14185-01    N/A  float (not Trac, 90 deg different)
14 1 1 1 1  3L5-14190-00  N/A    float needle = Trac 10206
15 1 1 1 1  603-14186-00 $4.00 hinge pin Ø2 x 16
16 1 1 0 0  3L5-14112-25    N/A  throttle slide
16 0 0 1 1  3L5-14112-40    N/A  throttle slide
17 1 1 1 1  3L5-14137-00 $5.00 spring stop “M” clip
18 1 1 1 1  3L6-14116-06    N/A   jet needle 3X1  Ø2.0 Ø1.36 x 30.7
18 1 1 1 1  36R-1490J-06    N/A   jet needle set 17, 18, 20  3X1
19 1 1 1 1  174-14131-01 $9.00 throttle spring Ø10.5 x 52
20 1 1 1 1  127-14137-00 $2.00 jet needle clip    Ø2.0
21 1 1 1 1  3L6-14133-00 $0.00 idle speed screw spring
22 1 1 1 1  36R-14103-00 $0.00 idle speed adjust screw
23 1 1 1 1  58E-14171-00 $0.00 choke plunger
24 1 1 1 1  127-14135-00 $0.00 choke spring
25 1 1 1 1  98580-05012  $0.60 top cover screw M5 x 12 phillips
26 1 1 1 1  92990-05100  $0.25 top screw washer M5 spring type
27 1 0 0 0  3L5-14123-01 $0.00 early idle air mixture screw (’79-81)
28 1 0 0 0  3L5-14962-00 $0.00 early idle air screw washer (81 only?)
29 1 1 1 1  95380-05600  $1.50 clamp nut M5 x 5 hex9
30 1 1 1 1  98517-05030  $0.70 clamp bolt M5 x 30 pan phillips
31 1 1 1 1  90445-05N13  $0.00 drain hose 200mm
32 2 2 2 2  3F7-14134-00  $5.00 air and drain screw spring Ø4.8 x 10
33 1 2 2 2  36R-14104-00  $6.00 air and drain screw M6-0.75×20
34 1 1 1 1  1M3-14997-00   N/A  clamp seal Ø23
35 1 1 1 1  1V3-14271-00   N/A   clamp sleeve Ø18 x Ø23 slotted
36 0 0 1 1 not sold separate N/A  top cover with curved pipes
39 0 0 2 2  17L-14106-00 $2.50 cable adjuster nut M6-0.75×3 hex9
40 0 0 2 2  17L-14106-00 $6.00 cable adjuster
41 0 0 2 2  180-14169-00 $0.00 cable rubber cap
41 0 0 2 2  WPS-70-1028  $3.00 rubber cap similar, newer style

.

.

.

2. Mikuni H9-10 on Indian, R4-13 on Trac (Daelim)

H9 is a 10mm carb with a 18mm clamp diameter.
R4 is a 13mm carb with a 20mm clamp diameter.

They look almost the same, and share many parts in common.

1979-84 Indian mopeds, some

1984-90 Trac mopeds with Daelim engine

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Mikuni H9-10 and R4-13

Combined Parts List         L = Trac Liberty, Escot, Image  O = Trac Olympic
0 quantities Trac#  new xx   C = Trac Clipper, Hawk, Sprint   I = Indian AMI50 
0 quantities Trac#  new  
01  L O C I  Trac#  Trac# xxIndian# xx price   description   
00  1 1 0 0  12201 13201 E000-00-00   N/A    carburetor Trac Liberty R4-13
01  0 0 1 0  00000 13202 E000-00-00   N/A    carburetor Trac Clipper R4-13D
01  0 0 0 1  00000 00000 E210-30-50   N/A    carburetor Indian AMI50 H9-10   
01  1 1 1 0  12201 13201 E000-00-00   $75   carburetor body bare Trac
01  0 0 0 1  00000 00000 E210-30-50   N/A  carburetor body bare Indian
02  1 1 0 1  12211 13215 E237-70-50   N/A    needle jet E8 Ø2.05
02  0 0 1 0  00000 13216 E000-00-00   N/A    needle jet D8 Ø2.10
03  1 1 1 1  10206 00000 E238-80-50   N/A    float needle Yamaha 3L5-14190-01
04  1 1 1 0  10201 00000 E000-00-00  $0.00 idle jet 40, thread M4-0.7
04  0 0 0 1  00000 00000 no number     N/A   idle jet not-replaceable, tight press
05  0 0 0 0  00000 00000 E236-00-50  --N/A- main jet 60, M5-0.75 small round
05  0 0 0 1  00000 00000 E236-25-50  $8.00 main jet 62.5  use Dellorto  #60
05  1 1 0 0  12205 13206 E000-00-00  --N/A- main jet 65 use Dellorto 1486 #62
05  0 0 1 0  00000 13207 E000-00-00  --N/A- main jet 70 use Dellorto 1486 #68
06  1 1 1 1  12218 13223 E238-10-50    N/A   float white-clear plastic (not QT50)
07  1 1 1 1  10207 00000 E238-07-50  $4.00 float hinge pin Ø2 x 16
08  1 1 1 1  12203 13204 E238-00-50    N/A   float bowl gasket
09  1 1 1 0  12204 13205 E000-00-00    N/A   float bowl no vent
09  0 0 0 1  00000 00000 E238-30-50    N/A   float bowl w/vent
10  2 2 2 2  10202 00000 E237-06-50  $0.70 float bowl screw M4 x 14 phillips
11  1 1 1 1  12217 13222 E238-12-50  $0.60 top cover screw M4 x 25 phillips
12  2 2 2 2  10203 00000 E237-01-50  $N/A   rubber cap original short
12a2 2 2 2 10203a00000 E237-01-50a $3.00 rubber cap substitute 70-10228c
14  0 0 0 1  00000 00000 E237-02-50    N/A   top cover, smooth cable holes
15  1 1 1 1  12213 13218 E237-04-50    N/A   top gasket
16  1 1 1 1  10204 00000 E238-16-50 $9.00 throttle spring Ø10.5 x 52 
17  1 1 1 1  12207 13209 E237-11-50  $6.00 spring plate (can use “M” clip)
18  1 0 0 0  12210 00000 E000-00-00  $0.00 jet needle 3J2-3 Ø2.0 
18  0 1 0 0  00000 13213 E000-00-00  $0.00 jet needle 3X6-4 Ø2.0
18  0 0 1 0  00000 13214 E000-00-00  $0.00 jet needle 3T6-4 Ø2.0 Ø1.45 x 31.9
18  0 0 0 1  00000 00000 E237-08-50 $0.00  jet needle 3G1-6 Ø2.0 Ø1.40 x 34.4 
19  1 1 1 1  12206 13208 E237-12-50  $2.00 needle clip    Ø2.0
20  1 1 0 1  12216 00000 E238-14-50    N/A   throttle slide Ø14 x 20, says 2.0
20  0 0 1 0  00000 13221 E000-00-00    N/A   throttle slide Ø14 x 20, says 4.0
21  1 1 1 1  12213 13218 E237-04-50  $1.50 clamp nut M5 x 4 hex9
22  1 1 1 1  12220 13225 E238-02-50  $0.00 choke spring Ø6 x 19
23  1 1 1 1  12219 13224 E238-06-50  $0.00 choke plunger Ø8 x 20
24  1 1 1 1  12212 13217 E237-05-50  $0.60 clamp screw M5 x 25 phillips
25  1 1 1 1  12208 13210 E237-10-50  $9.00 idle spd screw M6-0.75×17 short tip
26  2 2 2 2  12209 13211 E237-09-50  $5.00 idle screw spring Ø4.8 x 10 (used 9)
27  1 1 1 1  10205 00000 E238-18-50  $6.00 idle air screw M6-0.75×20, long tip
28  2 2 2 0  10208 00000 E000-00-00  $N/A   cable rubber boot original
28a2 2 2 0  10208a 0000 E000-0 0-00  $2.00 cable rubber boot substitute 1476-06
29  2 2 2 0  10209 00000 E000-00-00  $6.00 cable adjuster-stop M6-0.75×16 hex7
30  1 1 1 0  12215 13220 E000-00-00   $19   top cover, threaded cable holes
31  4 4 4 0  10210 00000 E000-00-00  $3.00 adjuster lock nut M6-0.75 x 2 hex7
32  2 2 2 0  12222 13227 E000-00-00  $0.00 cable curved pipe M6-0.75
33  0 0 0 1  00000 00000 E000-00-00    N/A  clamp sleeve Ø18 x Ø23
33  1 1 1 0  00000 00000 E000-00-00    N/A  clamp sleeve Ø20 x Ø23

Mikuni cable rubbers

Indian Mikuni idle hole before and after drilling

 

 

 

 

 

 

 

 

Indian Mikuni carb service

The idle hole is often blocked. There are three spray holes, the main and mid-range under the throttle slide, and the smaller idle hole downstream of the throttle slide. When the bike is idling the slide is down and only the idle hole is active. A small slit of air under the slide blows over it, creating the suction and breaking up the liquid gasoline into small droplets. The drill size is tiny, a #76 which is 0.020 inch. The drill is held in a pin vise. The pin vise goes into the drill chuck. After about 2mm of depth there is a empty chamber behind the hole. That chamber leads to the idle jet which is at the top of a vertical tunnel-tube made into the zinc casting. The idle jet can be cleaned separately from below. It is smaller, like maybe 0.010 inch. That is smaller than the smallest drill #80 in a numbered set.

Carb spray is used to tell if the idle hole or idle jet is clogged. When sprayed up from the vertical idle tunnel-tube, the spray should shoot out from the mid range hole and dribble out from the idle hole.

 

3. Mikuni VM10-24 on Angel (TYM) mopeds

This carb is on Taiwan-made Angel and Speed Bird mopeds. It is a 10mm carburetor with a 20mm clamp diameter.

It is a 1960’s to early 70’s design, like a 1965 Yamaha U5 Newport, or a 1970 Suzuki F50 Cutlass carburetor. It has a brass swinging twin-float and a replaceable float needle seat. It has nothing made of rubber in it, unlike more modern carburetors. 

1977 Angel AP48

1983 Angel BP48-S carb

1979 Angel BP48-S

1977 Speed Bird BP48

 

 

 

 

 

 

 

 

 

 

 

 

Mikuni VM10-24

Parts List
 #    Angel part #  Trac#   price      description
00  786-01-31000 00000     N/A  carburetor assy
01  786-01-3100a 00000  $0.00 carburetor body bare
02  786-01-31510 00000  $0.00 cable rubber boot
03  786-01-3110a 00000  $0.00 carb top M20-1.0 thread
04  786-01-31440 00000    N/A  throttle spring Ø13 x 38 stiff original
04  786-01-3144a 00000  $6.00 throttle spring Ø13 x 50 soft substitute
05  786-01-31380 00000  $0.00 spring plate Ø13 Ø2.5
06  786-01-31340 13208  $2.00 needle clip Ø2.0
07  786-01-31330 00000    $15  jet needle 3G9  Ø2.00 Ø1.60 x 34.4
08  786-01-31470 00000    $45  throttle slide Ø16 x 23.5, says 2.0
09  786-01-3120a 00000  $5.00 cable adjuster-stop M6-0.75  hex7
10  786-01-3120b 10210  $3.00 adjuster lock nut M6-0.75 x 2 hex7
11  786-01-3120c 00000  $0.00 choke housing M10-1.0 thread, pipe thread subst?
12  786-01-31490 00000  $0.00 choke spring Ø6.5 x 23 stiff
13  786-01-31480 00000  $0.00 choke plunger Ø8 x 17.5
15  786-01-31520 13218  $1.50 clamp nut M5 x 5 hex9
16  786-01-31530 00000  $0.00 clamp screw M5 x 27 slot-hex8
17  786-01-31450 13211  $5.00 idle (both) spring Ø4.8 x 10
18  786-01-31460 00000  $6.00 idle air screw M6-0.75×19, long tip (-1)
19  786-01-31540 13210  $9.00 idle speed screw M6-0.75×17 short tip
20  786-01-31370 00000  $0.00 idle jet 15
21  786-01-31320 00000  $0.00 needle jet E2-137 Ø2.05
22  786-01-31300 00000  --N/A- main jet 45 M5-0.75 small hex
23  786-01-3139a 00000  $0.00 float seat seal washer Ø7 x Ø10
24  786-01-3139b 00000  $0.00 float valve seat M7-0.75 thread hex8
25  786-01-3139c 00000  $0.00 float valve needle
26  786-01-31350 00000     N/A  float
27  786-01-31410 00000  $4.00 float hinge pin Ø2.5 x 23
28  786-01-31360 00000     N/A  float bowl gasket
29  786-01-3100b 00000     N/A  float bowl
30  786-01-31430 10202  $0.70 float bowl screw M4 x 14 phillips
31  786-01-3100c 00000  $0.00 float overflow hose Ø3 x 200
32  786-01-3100d 00000     N/A  clamp sleeve with lip Ø20 x Ø23 x 15.5
34  786-01-3110b 10209  $6.00 cable adjuster-stop M6-0.75 x 16 female hex7
35  786-01-3110c 00000  $3.00 adjuster lock nut M6-0.75 x 2 hex7
36  786-01-3110d 00000  $0.00 carb top rubber cap
37  786-01-3110e 00000  $0.00 curved pipe cable guide

 

Angel Carb Service:

Angel service p9

Angel service p10

Angel service p11

Angel service p12

 

 

 

 

 

 

 

 

 

 

 

4. Mikuni design

A. Pacco

The India-made Pacco P-60 MT carburetor used on 2000-2002 Avanti mopeds

Pacco P-80 MT carburetor 21mm clamp diameter, same as Dellorto SHA 15/15

Pacco P-60 MT carburetor, 21 clamp diameter
Left, Dellorto SHA 15/15, same 21 clamp size

avanti-pacco-carburetor-16-0-mm-slide-and-top-parts

Pacco P-60 MT carburetor, 16mm slide parts

 

 

 

 

 

 

 

.

 

 

 

B. Mikcarb

The India-made Mikcarb is used on 2005 Hero Majestic Pacer. It looks identical to Pacco P-60, except it has a cable choke instead of a flip lever.

Mikcarb on 2005 Hero Majestic Pacer

 

 

 

 

 

5. Mikuni Jets

Small Hex used on 1960’s-70’s Yamaha and Kawasaki
045    --N/A-  Angel #786-01-31300
050      N/A
060      N/A
070    $3.00
075    --N/A-
080    $3.00
085    $3.00
090      N/A
100      N/A

Small Round used on many Yamaha, Kawasaki, and Suzuki products
060    --N/A-  Indian #E236-00-50
062.5 $8.00  Indian #E236-25-50
065    --N/A-  Trac #13206
070    --N/A-  Trac #13207
075    --N/A-
080    --N/A-
090      N/A
100      N/A
110      N/A
116    $3.00
118    $3.00
120    $3.00
124    $2.50
132    $2.50
140    $3.00
150    $2.00
155    $2.50
160    $3.00

Large Round  used on many Yamaha, Kawasaki, and Suzuki motorcycles
060    --N/A-
062.5 $8.00
065    --N/A-
070    $8.00  Yamaha #620-14231-14-00
075    --N/A-
080    --N/A-
090      N/A
097.5 $2.50
100    $2.50
102.5 $2.50
105      N/A
107.5 $2.50
110    $2.50
112.5 $2.50
115      N/A
117.5   N/A
120    $2.50
122.5   N/A
125    $2.50
127.5 $2.50
130    $2.50
132.5 $2.50
135      N/A
137.5 $2.50
140    $2.50
142.5 $2.50
145    $2.50
147.5 $2.50
150    $2.50
152.5 $2.50
155    $2.50
157.5 $2.50

 

6. Info

These are the baby Mikuni’s, the smallest of the small, 10 to 13mm for limited 50cc engines. Unlimited 50cc like Kawasaki AR50 or Yamaha YSR50 have 18mm size carburetors. Those are bigger babies, but still “off the charts”.

USA motorcycle parts suppliers commonly have parts for 28 to 44mm Mikuni VM series (classic round slide) carburetors. They have 2.5 or 3.0mm jet needles, not 2.0 like the “babies” have. Their float needles are also bigger.

Yamaha, Suzuki, and Kawasaki supply some parts for the small Mikuni carburetors that are on their 50cc models.

 

Carb clips

 

Jet Needle Clips are tiny and get lost easily. The full name of that kind of clip is “metric side-mount external retaining ring (E-style)”. The clip size for moped carburetors is smaller than any motorcycle carburetor clip, because the jet needle and everything else in the carburetor is smaller. A 10mm Indian moped carb jet needle is 2.0mm thick with a 1.5 clip groove. Mikuni carbs 18mm and up have needles 2.5mm thick with a 1.9mm clip grooves, or bigger.

 

 

 

 

Sources:

  1. Parts Catalogs provided illustrations, part numbers, descriptions, applications, and some specifications.
  2. Service Manuals provided most specifications.
  3. Packaging Labels on some new parts provided part numbers and applications.
  4. Markings on some used parts provided specifications.
  5. Direct Measurement on most parts provided specifications.
  6. Internet Images provided some identification by photo-matching, and occasionally dimensions by photo-scaling.

 

 

7. Tillotson HK25A Carb on ’78 Indian AMI-50

Carb kit Rk-32Hk

 

Tillotson HK25A Carburetor Parts (none)
 E210-12-50 Tillotson carb comp.   none  has no float reservoir

These have an adapter “bell” for the air filter, to interchange with Keihin. These did not work well when they were new with fresh rubber back in 1978. Tillotson carbs were replaced by Keihin, only months after they came out. 40 years later in 2018 their rubber parts, especially the diaphragm, are all stiff. This is the Tillotson carb kit for Indian, Rk-32Hk-4911, available on Amazon.

 

Tillotson carb, front and back view

Tillotson carb on 1978 Indian

 

Gurtner Carburetors

July 14, 2016

Gurtner

Contents (carburetor families):
1.  AD  on ’81-83 Motobecane   
2. D, E on ’75-83 Peugeot 102, 103
3. AR2 on ’70-80 Motobecane 40, 50
4. AR1 on ’66-78 Motobecane 7, Cady
5.  BA  on ’60-69 Motobecane, Raleigh
6.  AR  on ’55-65 Motobecane, Riverside
7. Floats
8. Jets
9. More  

 

Jules Gurtner started making carburetors in 1907, for some of the earliest automobiles and motorcycles.

Gurtner carburetors are made in France, and original on French mopeds Peugeot and Motobecane. See also mopedarmy.com

Gurtner early M18D M20D M22D M23.5D M25D

1940’s M series

Gurtner early M series article from 1945

1945 M series

 

 

 

 

 

 

 

 

Gurtner Master Catalogs: Here are the 1961 Gurtner Catalog and the 1980 Gurtner Catalog from motobec.fr. 

Gurtner Moped Carburetors: Here are the 1961 Carb List and the 1980 Carb List. From those you can see that about one third of all Gurtner carbs are for mopeds (mobylettes). Before 1960, most Mobylettes had 10mm carburetors (or 8.7). So the speed and power were limited to be under about 25mph. After 1959, some had 10mm carbs and went 25mph, and some had 13mm carbs and went 30-35mph.

Much of this information and photos are from the Motobecane Club of France.

 

 

 

1. M Gurtner AD

 

Jet type 9831, float 13105, slide 13138 (∅15?) or 13416 (∅15?)

AD was the last Gurtner carburetor on Motobecane/MBK mopeds, before the change to Dellorto SHA.

 

1A. AD Carb List

AR2float 0 slide 0000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅13 AD13-858-A  7/82  parts list
’80-82? Motobecane 99Z, 94Z
13105  13138 ∅15? 9831/78   13345 0  13104  13185

∅13 AD13-915   parts list
’80-82? Motobecane/MBK 51V
13105  13416 ∅15? 9831/78   11316 0  13534  11301

∅13 AD13-945   parts list
’80-82? Motobecane/MBK 51S
13105  13416 ∅15? 9831/76   14097 0  13534  11301

 

 

2. Peugeot 1980 tiny D and E

 

Jet 5012, float 6437, slide 4649/10 (∅11?) or 4649/8 (∅13)

102 has a fixed engine and piston port intake, to cylinder.
103 engine swings and has a reed valve intake, to case.
USA versions: U1 (20 mph), U2 (25 mph), U3 (30 mph)

Left, 102 has a fixed engine and piston port intake, to cylinder. R, 103 engine swings on the swing arm pivot, case reed intake.

Gurtner Peugeot remake

generic D12G remake

D12G-724F for 103

1980 102 SP U3 D12.698.G.1.80

D12G-698 for 102

 

 

 

 

 

 

 

2A. D Parts List

102 and 103 combined. Part numbers with “b” are 102-only.
New items prices are green. Used prices are dark green.

1970's 103 types had Gurtner D12 carburetors. '81-on 103/104 had Gurtner E12B carburetors. 
Original Carburetors with air cover   
fig price  Peug#  Gurtner#   jet slide  US/EU models
1a none 00000 D10G-754B 250 11 70’s 103 00  25kph
1a none 00000 D10G-918B 230 11 70’s 103 CH 30kph
1a none 48929 D12G-724C 245 13 76-80 103 0 25-30
1a none 00000 D12G-724E 245 13 70’s 104 L, LV 
1a $83.000000 D12G-724F 255 13 replacement 25-30
1a none 58036 D8.5G-826  240 11 76-80 103 0 20mph
1b none 46479 D12G-698   245 13 79-80 102 0 30mph
1b none 64203 D10G-975   220 13 79-80 102 0 25mph
1c  none 00000 E12B-738    000 00 81-83 103 0 25-30

fig  price   Peug# Gurtner# MB#  Carburetor Parts
2    $45.0 48929 carb 48929 bare   good used, tested
3    $15.0 69299 4649/8 15319 throttle slide Ø13 
3    none  69445 4649/10 throttle slide Ø?? for D8.5G-826
4    $5.00 53386 17732 14107 spring Ø9.5 x 30
5    10-$7 12156 carb top bare
5    $12.0 12156 7701 top assy 5,6,8,9,10,12,13  no slide
6    $1.00 07016 10218 14311 screw M4 x 12 
7    $4.00 09939 9939 air filter bracket
7b  $0.208560993660 01088 lock washer   
8    $5.00 01510 1510 00189 adjuster M6-0.75 
9    $2.50 01511 1511 04172 adjuster nut      
10  $3.00 08947 8947 drawing rod washer 
11  $8-$5 09394 9394 drawing rod gasket 
12  18-12 09393 9393 drawing rod 
13  $8.00 09391 9391 throttle pull clip  a wire “crankshaft”
14  $2.00 06546 6546 18892 idle screw M5-0.8
15  $2.00 05072 5072 00204 idle screw spring
15  none  06546 13667 idle screw and spring
16  none  69463 5012/66 jet 260=66 0.64  (0.025″)
16  none  69462 5012/64 jet 255=64  
16  none  69461 5012/63 jet 250=63 0.63 mm
16  $19.0 69460 5012/62 jet 245=62 0.62 mm
16  $11.0 69459 5012/60 jet 240=60 0.60 mm
16  $14.0 69458 5012/59 jet 235=59 0.59 mm
16  $14.0 69457 5012/58 jet 230=58 0.58 mm
16  none  69456 5012/56 jet 220=56 0.56 mm
17  $2.00 69300 fiber washer 19 x 12.5 x 0.4   optional
18  55-35 69755 float cover w/seat     
19  $5.00 09348 9348 rubber ring 22 x 27 x 1  
20  $5.00 69754 12372 plug M12-1.0 taper seal, no gasket
21  $2.00 08048 8048 float cover strap  for 103
21b $12.009365 9365 float cover strap  for 102
22  $0.60 10306 10306 13392 screw M5 x 10       
23  $24.0 06437 6437 float with needle Gurtner         
23  $14.0 06437 5440 float w/needle aftermarket
24  $8.00 04159 4159 14133 fuel filter screen
25  none  09860 9860 air box with filter   for 103
26  $12.0 09672 9672 air filter gasket          
26b $39.0 09388 9388 air box with filter   for 102
27  $15-9 09286 air box screw for 103 #1 original
27  $16.0 09286 air box screw for 103 #2 replacement
27  $10.0 09286 air box screw for 103 #3 or 4 original
27b $22.0 09395 air box screw for 102 #5 original
27b $16.0 09395 air box screw for 102 #6 replacement
28  $1.00 68239 9617 19689 screw M3-0.5 x 6
29  $6.00 68239 clamp bolt M6 special  
30  $0.3083208700010 clamp bolt nut
31  $10.0 68202 23134 mount clamp w/bolt  


Air box screw for Peugeot 102 and 103

 

 

 

 

 

3. M Gurtner AR2 

 

Jet type 581, float 4901, slide 4649/10 (∅13) or ????? (∅14)

Gurtner AR212/R705 remake

AR2-12-705 remake

Gurtner AR210-R991

Gurtner AR2-10-991

 

 

 

 

Gurtner AR2 series moped carburetors have a large flange, like a wall. It is for an “air box”, a noise silencing, fuel mist recovering, and air filtering chamber. There are two (venturi) sizes, 10 or 12 mm, and two styles, side or center mount. Center and side mount carbs look the same, but don’t interchange completely.

 

3A.  AR2 Parts List

Key: A= center mount carb only   B = side mount only
New prices are green. Used prices are dark green.

  

Original Carburetors without air cover   S is air box stud
fig price  MB#   Gurtner# 0 jet diffuser S US/EU models   mph
B none 00000 AR2-13-712 00   00000 0 70’s SP94 00 00   ?
A $110 20026 AR2-12-705 54   19990 0 74-76 50V 00 00 30 
B none 54973 AR2-12-873 56   22937 5 76-79 50V 00 00 30
B $180 54973 Ø12 07776   56   22937 5 orig replacement 30
B none 54973 AR2-12-978 56   22937 6 79-80 50V 00 00 30
B none 54973 Ø12 13512   56   21002 6 orig replacement 30
B $120 22160 AR2-12-729 56   21002 5 74-77 50 40   25-30 
B none 22160 AR2-12-729 56   21002 6 78-80 50 40   25-30 
A none 52175 AR2-10-759 52   54237 0 75-77 50V 00 00 25 
A none 52175 AR2-10-737 K80 52560 0 77-79 50V 00 00 25 
A none 52175 AR2-10-991 K80 52560 0 78-80 50V 00 00 25
B none 54115 AR2-10-910 52   20573 5 76-77 50V 50 40 20
B none 54115 AR2-10-910 52   20573 6 78-78 50V 50 40 20
B none 54115 Ø10 13510   52   20573 6 orig replacement 20

  fig  price    MB#  Carburetor Parts 
  1A $65.0 53657 carb body bare AR2-12-705
  1A none  52430 carb body bare AR2-10-991 & 737
  1B $50.0 54466 carb body bare AR2-12-873 & 729
  1B none  54235 carb body bare AR2-10-910
  2A $19.0 18355 air filter cover   for center mount
  2B none  20949 air filter cover   for side mount
  3A $12.0 15041 air filter screen  for center mount
  3B $6.00 20999 air filter screen  for side mount
  4A $12.0 18356 spring clip         for center mount
  4B $4.00 m6cup cupped washer upgrade, see above
  5B $1.00 m5lock M5 nylock nut   for M5 stud
  5B $1.00 m6lock M6 nylock nut   for M6 stud
  5B $2-$1 13339 M5 knurled nut  for M5 stud
  6B $5.00 21000 stud 5mm         side mount pre-79
  6B $8.00 23562 stud 6mm         side mount 78-on
  6B $5.00 special M6-M5 step stud for stripped M5 hole
  7B $3.00 20997 air filter gasket  18 x 21 x 1.5mm
  8B $8.00 20996 air filter 5mm     side mount pre-79
  8B $20.0 23561 air filter 6mm     can drill a 5 to 6
  9   $1.00 19689 taper screw M4-0.7 x 6/8 on USA models
10   $1.00 19767 bolt M5-0.8 x 44    M5 w/flange 10 hex
11   $2.00 15326 fiber washer 5mm 5 x 10mm
12   $6.00 20475 o-ring 21×24 x 1.5  this is optional
12   $0.00 somehow, removing this often makes it leak less
13A $5.00 00189 adjuster M6-0.75   A13
13B $16.0 21940 cable guide, used   for side mount
13B $14.0 substitute 2cr + 3a Dellorto cable pipe
14   $0.50 18893 screw M5-0.8 x 12  
15   $0.20 01271 washer M5           
16A $12.0 21229 slide cap M6-0.75   threaded for adjuster
16B $5.00 21696 slide cap                recessed for elbow
17   $5.00 14107 spring Ø9.5 x 30    same as Peugeot
18   $15.0 15319 throttle slide Ø13   for AR2-10 & Peugeot
18   $15.0 19278 throttle slide Ø14   for AR2-12 carbs
19   $7.00 14120 choke spring       
19B $2.00 22935 choke cable ring    cable end adapter
20   $9.00 14119 choke slide brass   stepped 6.3 x 5.7 x 15
20B $8.00 22936 choke push rod      original white plastic
20B $3.00 22936 substitute (adjuster A2)
21   $2.00 00204 idle spring 7.5 x 11 
22   $2.00 18892 screw M5-0.8 x 16  same as Peugeot
23   $5.00 00208 bolt assy M6-1.0 
24   $3.00 00878 tall nut M6-1.0   12mm tall 8mm hex
25   $2.00 15043 clamp for ∅21.7 (to 3/78)
26   $10.0 23134 clamp for ∅23.5 (4/78-on) 
26A none  14100 sleeve 19×16 black   for AR2-10-991
26A $21.0 16630 sleeve 19×17 white  for AR2-12-705
26B none   22689 rubber washer 15 x 19 x 2
27   $6.00 18880 float gasket   
28   $8.00 14133 fuel filter/screen     same as Peugeot
29   42-25 14101 float Gurtner 4901 41.4 x 23.6 
29   $12.0 14101 float aftermarket   40.3-40.9 x 22.6-22.7
30B $38.0 22937 slide fit diffuser Ø0.91  AR2-12-873 & 978
30A $7.00 19990 9346/1 diffuser Ø1.50  AR2-12-705
30A none  20573 9529/3 diffuser Ø0.00  AR2-10-910 pre-78
30A none  54237 slide fit diffuser Ø1.50  AR2-10-910 ’78-on
30B $35.0 21002 slide fit diffuser Ø0.91  AR2-12-729
31   $3.00 20000 collar M7-1.0           holds slide-fit diffuser
32   $1.00 19689 screw M3-0.5 x 7     M3 taper seal
33   none  52560 press diffuser Ø0.61 AR2-10-991 & 737
34A none  21228 float top horiz inlet   for center mount
34B none  22161 float top vert inlet    for side mount
35   none  22339 float top no inlet      for carb w/inlet
36   $17.0 23545 581/52 jet 0.52 mm 210cc  for AR2-10-910
36   none  21841 581/52 jet 0.52 mm   #52  
36   $10.0 23546 581/54 jet 0.54 mm 220cc  for AR2-12-705
36   $14.0 21843 581/54 jet 0.54 mm   #54  for 
36   $19.0 23547 581/56 jet 0.56 mm 230cc  AR2-12-873 & 978
36   $19.0 21949 581/56 jet 0.56 mm   #56  for AR2-12-729
36   $15.0 00000 581/57 jet 0.575mm   #00 drilled w/#74 drill
36   $19.0 23548 581/58 jet 0.58 mm 240cc  for AR1-10
36   $19.0 22938 581/58 jet 0.58 mm   #58  
36   $19.0 23549 581/60 jet 0.60 mm   #60  for AR1-10
36   $15.0 00000 581/61 jet 0.615mm   #00 drilled w/#73 drill
36   $15.0 00000 581/64 jet 0.64 mm    #00 drilled w/#72 drill
36   $19.0 51052 000/00 jet 0.80 mm   K80  AR2-10-991 & 737
40   $17.0 aftermarket AR2 Carb Kit correct only for AR2-12-705

 

 

3B.  AR2 Information

Side mount carburetors have threads for an air filter stud, side holes for a center mount air box clip, and clamp to a 19mm intake pipe. The side mount float top cover has a vertical fuel hose spigot. A stripped bare side mount body, as is, will exactly replace a bare center mount body.

Motobecane 30mph variator side-mount carb with long pipe

side mounted AR2 carburetors

Motobecane 20mph no-variator side-mount carb with thin long pipe

side mount thin pipe

40TS side mount with top-pull choke

 

 

 

 

 

 

 

 

Center mount carburetors have no threads in the stud hole, side holes for a center mount air box clip, and have removable sleeves, black 16 x 19 (for AR210), and white 17 x 19mm (for AR212). The sleeves reduce the precision clamp size from 19mm to 16 or 17. The purpose is to be tamper resistant. The sleeves fit tight and are difficult to remove without damaging them. The center mount float top cover has a horizontal fuel hose spigot. A stripped bare center mount body, after threads are cut in the air box post hole, will replace a bare side mount body.

Motobecane 30mph variator center-mount carb with short pipe

center mounted AR2 carburetors

 

Center mount early  Some pre-USA years 1960’s or early 1970’s had no fuel hose inlet in the float top cover. Instead it was in the carburetor body just below the float top. This type is in many Motobecane USA parts illustrations, but it was not used on any, or hardly any US models. In the illustration below it was edited out. Out of 47 original carbs, taken off once-living Motobecanes from around Southern California, none were this “center mount early” type with the fuel hose spigot in the carb body.

 

OEM Replacements Motobecane USA 1976-80  
7776 is pre-1978 12mm, 5mm stud, thin mount.
13512 is 1978-on 12mm, 6mm stud, thick mount.
13510 is 1978-on 10mm, 6mm stud, thick mount.

In 1977 the air box stud 5 mm threads would sometimes get stripped, or the clamp mounts would sometimes break. So during 1978, on some they made the air box stud 6 mm and the casting thicker at the mount. From 1979-on all were 6 mm.

MB carb mounts early (thin) and late (thick).

MB carb mounts
early (thin)
and late (thick).

 

Mount Type: All Motobecane carbs clamp to 19.0mm inlet pipes. But many of the pre-March 1978 carburetors were cracking at the edge of the clamp, or the base of the petals. So Gurtner beefed up the carb body with a reinforcing ring, made the clamp petals about 1mm thicker each, and changed the clamp to the bigger Peugeot double-wall type.

Air Filter Stud: When the mount was made stronger in 1978, the air filter post was also beefed up from 5mm to 6mm. This made the threads in the body more resistant to stripping. Another issue that was improved is when the air filter stud is over tightened, a bulge can form in the float chamber wall behind it. That bulge makes the float stick. See below.

Center Mount Air Cover: The center mount type (short and deep) air box is too deep and sticks out too much as a side mount. The right side engine cover panel must be removed, and some kind of high-offset right pedal crank arm installed. Then maybe pedal threads are different.

Side Mount Air Cover: The side mount type (tall and flat) air box is too tall and hits the frame as a center mount. More importantly, they break, fall off, and get thrown away, in addition to getting lost. Because of that, they have become scarce and pricey. From 2000-2015 maybe 200 people have asked for this item, but only two were available and sold at MM.

Gurtner Motobecane air box covers

Three views of the side (L) and center (R) types of MB air box covers

 

Motobecane side mount air box nut and cupped washer upgrade

Side mount air cover breaks without cupped washer/nut.

The Motobecane piston-port two-stroke engine needs the air cover because the gasoline mist flows in and out in both directions. So there is a little cloud of fuel and oil mist out in front of the carburetor. Without the air cover, this fuel cloud gets wasted and blown away (or ends up on the riders right leg or shoe). Besides that, the air cover provides the correct amount of flow restriction, which is a good thing, up to a point. See below about running without an air cover (how it can damage the engine by over-heating from not enough fuel and oil).

 

 

Air cover substitution: Here is a center-mount air cover installed on a side-mount carburetor. Holes have to be drilled for the mounting wire clip, and the lower right corner has to be warmed up and molded inward where it touches the round magneto base plate. More importantly, the side cover must be removed, and it almost touches the pedal. So it’s easy to kick it when pedalling.

Choke Slide: This is often mysteriously missing, but actually stuck in the lowest (normal) position, either by tar or corrosion. It can be unfroze with solvent and/or by removing the cable wire and pushing it up from the bottom by tapping with a small punch and hammer. When the choke slide is pulled up, the choke is “on” for cold starting, and an extra fuel path is exposed by the step in the choke slide. If the choke slide is actually missing, the choke would be “on” all the time, but some extra air gets in along with the extra fuel. So the net effect of running without a choke slide is minor. 

Top Pull or Bottom Pull Choke Cable:

1. On center mount carburetors, for variator models, the choke cable is “top pull”. The choke and throttle cables detach, allowing the carburetor to be serviced away from the bike.

Gurtner MB Top pull choke cable routing

Gurtner AR2 top pull choke cable routing

2. On side mount carbs for non-variator (Dimoby) models, the choke cable is “top pull”, but has a elbow (curved tube), like the throttle cable. The choke and throttle cables detach, allowing the carburetor to be serviced away from the bike.

Gurtner MB bottom pull choke parts exposed

AR2 bottom pull choke parts exposed

3. On side mount carbs for ’78-later 30mph variator models, the choke cable is “bottom pull”, where the choke wire runs through the carb body, trapping it on or near the bike. On those most service operations are done with cables attached, about one foot away from the bike. To remove the carb you have to pull the choke wire all the way out. Then it won’t usually go back because the braided end gets frayed. Then the choke wire has to be replaced. 

 

 Le Diffuseur: When you look down the “throat” or venturi of a Gurtner carburetor, with the throttle wide open (throttle slide up and out of the way of the air), the little brass tube that sticks up from the floor of the venturi is the diffuser. It sprays the gasoline mist sucked up by the moving air.

Left, top are the way more common type, the “slide fit” type diffusers. Can you see, besides the main large hole down the middle, that each diffuser has two small holes facing out of the page? Those are the idle holes. When they are blocked, the engine will run OK, but will not run slow or “idle”. On a 21002 diffuser the idle holes are 0.016″. That size hole is cleaned with a #78 drill, also 0.016″.

Left, bottom are the less common type, the “press fit” type diffusers. You can only see one idle hole on this kind, but there is another on the opposite side. These diffusers have a very small center hole, that serves has the limiting jet. They are installed by pressing in from above, instead of sliding in from below like the other kind. The purpose of this type is to be tamper resistant. There is no particular direction that they have to be aimed at, and no flat side in the carb body for that purpose.

 

Motobecane 20mph carb sliced in half

Slide Fit and Press Fit Diffusers: Some Motobecane carburetors have “press fit” diffusers, instead of the usual “slide fit”. This is one of those types (AR2-10-737 or AR2-10-991 or perhaps others) that has been sliced in half to expose it’s secrets.

While “slide fit” diffusers slide in and out from the bottom, this “press fit” diffuser 52560, and carburetor type, slides (presses actually) in or out from the top. Many of these get smashed on top by Motobecane mechanics trying to push the diffuser downwards, the normal way out.

Press-fit-diffuser carburetors cannot be made to accept slide fit diffusers. 

 

Motobecane Choke Circuit cut away

Choke (cold starting) system: Unlike the Peugeot Gurtner and most other moped carburetor chokes, the Motobecane Gurtner AR2 has an additional fuel path or tunnel. It’s “choke” is a fuel enrichment device rather than an air restricting device. The choke circuit is completely independent of the main fuel circuit. It has it’s own fuel tunnel out of the float bowl, that bypasses the throttle slide, diffuser, and jet. 

Original Equipment Carbs have Dates: This carburetor clearly shows it’s manufacture date of 5/77, below the model number. It could be from a late 1977 or a 1978 bike. The 39 used Gurtner AR2 carburetors in Myrons Mopeds inventory on Dec 2014 have dates ranging from 03/74 to 04/80. The majority are from 1977 and 1979. See above “Population Study of Gurtner AR1 and AR2 Carburetors in Southern California”.   

 

 

4. M Gurtner AR1

 

AR1 has Gurtner jet type 581, float 5186 or 6758

Parts for five Gurtner AR1 carburetors are listed here, combined into one list using quantity colums a,b,c,d,e. 

 

a. Gurtner AR1-10-674 ’66-68 Motobecane Cady M1

 

b. Gurtner AR1-10-691 ’66-78 Cady M1P, PR, PRT, PRTS

MB Cady and MB 7 air boxes

 

c. Gurtner AR1-11.5-753 ’74-77 Cady M3PR, PRT, PRTS

 

d. Gurtner AR1-10-919 ’78 Motobecane 7 (US 20, 25)
e. Gurtner AR1-12-884 ’78 Motobecane 7 (US 30mph)

1978-79 Motobecane 7

Gurtner AR1-12 carburetor complete 3 views

In US mopeds, AR1 carburetors were only on one model for one year. That lone French pony was the 1978 Motobecane Model 7. Only about 2 or 4% of the Motobecanes sold in the US were Model 7.

 

AR1 Carb List

AR1float 0 slide 0000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅10 AR1-10-691  parts list
1966-78 Cady M1P, PR, PRT, PRTS
5186  8686 ∅00 00 581/B53    fixed 00  7679  4909

∅10 AR1-10-A691  parts list
1974-77 Cady M3PR, PRT, PRTS export
6758  8686 ∅00 00 581/B52    fixed 00  7682  11021

∅11.5 AR1-11.5-753  parts list
1974-77 Cady M3PR, PRT, PRTS
6758  4685/12 ∅00  581/B55   fixed 00  7681  11021

∅10 AR1-10-+919   parts list
1978 Motobecane 7 (20)
5186  8686 ∅00 00 581/B60   8669/1    7783  13289

∅10 AR1-10-919  3/78 parts list
1978 Motobecane 7 (25), 70’s M7
5186  8686 ∅00 00 581/B58   8669/2    7783  13289

∅12 AR1-12-884  11/77 parts list
1978 Motobecane 7 (30), 70’s M7
5186  4685/1 ∅14  581/B54   4687/3    7783  13289

 

Gurtner MB7

pic abcde price   MB#   Gurt#   description    remarks 

00 10000 none  00000 carburetor Ø10 AR1-10-674
00 01000 none  19600 carburetor Ø10 AR1-10-691
00 00100 none  00000 carbur.    Ø11.5 AR1-11.5-753
00 00010 none  54458 carburetor Ø10 AR1-10-919
00 00001 none  23021 carburetor Ø12 AR1-12-884
01 00001 none  54454 7782 carb body bare Ø12
01 11010 none  54225 carb body bare Ø10
02 00111 $2.00 23194 9754 top screw M4-0.75 x 22
02 11000 $2.00 17760 top screw M4-0.75 x 20
03 00111 $0.20 01088 3650 washer M4 lock
03 11000 none  00943 washer M4 lock
04 11111 none  17759 8002 carb top
05 11111 $7.00 14120 3936 choke spring    
06 11111 $9.00 14119 3935 choke slide  
07 11111 $5.00 14107 3771 throttle spring 9.7 x 29
08 11010 none  19605 8086 throttle slide Ø12  
08 00101 $35.0 16629 4685/1 throttle slide Ø14
09 11111 $2.00 00204 5072 idle screw spring
10 11111 $2.00 18892 6546 idle screw
11 11111 $5.00 00208 bolt assy
12 11111 $2.00 15043 4330 clamp
13 00111 none   22689 7088/1 seal ring 15 x 19 x 2
14 01000 none  19215 581/B48 jet 19 = 195cc = 48
14 01000 none  18973 581/B52 jet 20 = 210cc = 52
14 00001 $10.0 23546 581/B54 jet 22 = 220cc = 54
14 00010 $19.0 23548 581/B58 jet 00 = 240cc = 58
14 00010 $19.0 23549 581/B60 jet 24 = 245cc = 60
15 00011 none  23196 7783 air filter assy
16 00011 none  23195 13288 air filter mount
17 00022 none  23139 13432 screw M5x10 allen
17 00022 $0.60 subst. screw M5x10 phillips
17 22200 none  19248 screw M4x10
18 00011 none  14123 5186 float
18 11100 none  16113 6758 float
19 11111 none  14103 3764 float gasket
20 00022 $0.20 01088 3680 lock washer M4
22 22200 $0.20 00943 subst. lock washer M4
21 00022 $1.00 14106 10218 float screw M4x12 phillips
22 00011 none  19143 3752 fuel filter
23 00011 $2.00 15326 14025 fiber washer 5×10
24 00011 $0.60 13245 8176 bolt M5x10 hex
25 00122 $16.0 21940 cable guide 
26 00011 none  23197 13289 air box
27 22222 none  19606 10271 wood-type screw 4 x 13
28 11111 none  19145 8523 air box clamp assy
29 00011 $50.0 23199 12931 float chamber cap

 

 

 

5. M Gurtner BA

 

BA has Gurtner type 5012 jet, 6685 float

 

1962 Riverside 14030

BA Carb List

BAfloat 0 slide 00000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅10 BA10-549-D (BA-549-D)  7/60  parts list
1960 Mobylette
6685  4649/10 ∅13  5012/19    fixed 00  6747  4022

∅10 BA10-540-F (BA-540-F) 2/62 parts list  photos 1 2 3 4
1962 Riverside 14030
6685  4649/10 ∅13  5012/20    fixed 00  6747  4022

∅10 BA10-610-B (BA-610-B)  5/63  photos 1
1963 Raleigh RM6 Runabout
6685  4649/10 ∅13  5012/20?  fixed 00  6747  4022

∅10 BA10-610 (BA-610)  parts list  photos 1
1962 Motoconfort AU65, 60’s AV44, 76, 85
6685  4649/10 ∅13  5012/21, 20 fixed   6747  4022

∅10 BA10-610-C (BA-610-C)  10/63  photos 1 2 3 4
1962 Motobecane AV48
6685  4649/10 ∅13  5012/19   fixed 00  6747  4022

 

 

6. M Gurtner AR

 

AR has Gurtner type 3983 jet, 5186 float

 

 

1960 Riverside 14011

AR Carb List

ARfloat 0 slide 00000 jet  000 diffuser       air box
float 000 slide 00000  jet  000 diffuser   assm.   bare

∅10 AR10-429  parts image
1957-60 Riverside 14007A, 14010A, 14010B
5186  14124 ∅13 00  01122 0014126  00 000  15037

∅10 AR10-501  7/57  parts list
1957 Motobecane AV78 (variator)
5186  3100/10 ∅13  3983/21  5523 00  6747   4022

∅10 AR10-511  parts list
1950’s Motobecane, Dimoby (no variator)
5186  3763/8 ∅13 0 3983/20  5370 0    5946   5782

∅13 AR13-488-K  6/60  parts image
1960-62 Riverside 14010, 14010C, 14011, 14011A
5186  4685/14 ∅14  3983/21  4687 0 6904/2  4022

∅13 AR13-488  parts list
1961 Motobecane AV87 
5186  4685/14 ∅14  3983/21  4687 0 6904/2  4022

 

 

 

 

 

7. Gurtner Floats

 

 

Gurtner Floats

Gurtner 6437 and 4901

On 1970’s US mopeds there are 3 Gurtner floats:
5186 (Motobecane 14123) for AR1 carbs on Model 7
4901 (Motobecane 14101) for AR2 carbs on 40, 50
6437 (Peugeot 06437) for D-type carbs on 102, 103

Gurtner used to color code their new float containers green for Motobecane and red for Peugeot. Otherwise they are almost indistinguishable, unless together side by side. 

5186, 4901, 6437 specs

6685 specs

Float Service: On plastic types the needle is a press fit into the top and bottom holes in the bulb. The needle can simply need moving up or down. Or it could also need the tip straightened and/or sharpened/machined. Or the needle could need to be replaced, if it has become too short or too bent. Any piece of 1.5mm brass rod, cut to these lengths, and machined to a cone tip, would restore the float. In addition, a gasoline-proof sealant should be used to seal the press-fit holes, as a precaution, or if gasoline enters the bulb. 

Float List

Most data are from lesolex.com in France.
Most of these floats can be purchased there.
US models in blue.

13160 brass  for
needle ∅1.5 x 37.8, bulb ∅22.2
for chamber ∅23.4
1950’s Peugeot
superseded by 6437

13155 brass  for
needle ∅1.5 x 41.5, bulb ∅24.0
for chamber ∅25.2
1950’s Motobecane
superseded by 4901

6758 brass  for AR and AR¹ carbs
needle ∅1.5 x 41.7, bulb ∅22.7
for chamber ∅
for 66-78 Motobecane Cady
Motobecane #16113

5186 brass  for A, AR, AR1 carbs
needle ∅1.5 x 41.5, bulb ∅22.5 x 20.3
for chamber ∅23.6-23.9
’57-64 Ward (except 14030), 78 MB7
high bulb, Motobecane #14123

3739 brass  for C carbs: C10D
needle ∅1.5 x 41.7, bulb ∅22.5 x 20.3
for chamber ∅
for Peugeot Bima
low bulb, Peugeot #03739

6685A brass  for B, BA, BR carbs
needle ∅1.5 x 35.7, bulb ∅22.2 x 20.5
for chamber ∅23
60’s MB, Raleigh, ’61-63 Ward 14030
Motobecane #

6437 plastic for D carbs: D8.5 D10 D12
needle ∅1.5 x 37.8, bulb ∅22.0 x 20.1
for chamber ∅23.4
76-83 Peugeot 102, 103, 70’s BB
Peugeot #06437

4901 plastic for AR2 carbs
needle ∅1.5 x 41.5, bulb ∅24.0 x 20.3
for chamber ∅25.2
74-80 Motobecane 40, 50, others
wide bulb, Motobecane #14101

4901/2 plastic for E carbs: E12
needle ∅1.5 x 41.5, bulb ∅24.0 x 20.3
for chamber ∅
81-83 Peugeot 103, 80’s 104, GT10
wide bulb, Peugeot #

13105 plastic for AD carbs: AD13
needle ∅1.5 x 41.5, bulb ∅25.2 x 20.6
for chamber ∅
1980’s MBK 51, M16, 99Z 92GT
wider bulb, MBK #23135

 

 

 

 

8. Jets

 

 

There are three types of Gurtner jets (gicleurs), 581, 5012, and 9831. 

5012

M5.5-0.75 thread

 

 

581

M7-1.0 thread

 

 

9831

M7-1.0 thread

 

 

 

There are three size label types, here called 60’s, 70’s and 80’s.
A  581  jet, 60’s size 21, equals 70’s size 215, equals 80’s size 53.
A 5012 jet, 60’s size 21, equals 70’s size 215, equals 80’s size 54.
A 9831 jet, 60’s size 00, equals 70’s size 215, equals 80’s size 55.

Use this table to cross reference Gurtner sizes.

 

 

9. More

 

 

Population Study of Gurtner AR1 and AR2 Carburetors in Southern California

These 47 Motobecane carburetors all came from whole bikes that were stripped out for parts. The Motobecane population in the greater Los Angeles area is roughly represented by this large subset. Out of 47 carbs there were only two AR1 types, from Model 7. All of the 45 others were from Models 40 and 50. 

Year  Qty  Carb Type   Mount   Dates

1974   1  AR2-12-774   center  03/74

1975   7  AR2-12-705   center  07/75 07/75 07/75

1975   6   AR2-12-729   center  11/75 12/75 12/75 12/75

1976   8  AR2-12-705   center  01/76 01/76 01/76 01/76 01/76 03/76 10/76

1976   5   AR2-10-759   center  06/76

1977  13  AR2-12-705   center  01/77

1977   10  AR2-12-873     side   03/77 04/77 05/77 06/77 11/77 12/77 12/77

1977   10  AR2-12-729   center  02/77 04/77

1977   10  AR2-10-737     side   05/77

 1977   10 AR1-12-884    —–    11/77  11/77

1978   6  AR2-12-873     side   01/78 05/78 05/78 11/78 11/78

1978   1  AR1-10-919     side 03/78

1979   9  AR2-12-729   center  01/79

1979   9   AR2-12-873     side   03/79 05/79 05/79 05/79 06/79 07/79 07/79 11/79

1980   4  AR2-12-978     side   04/80 04/80 04/80 04/80

total  47

These are the surviving Motobecane carburetors that lasted longer than the rest of the bike. If there were times when the metal was weak, those months or batches would be missing from this collection, pretty much, because the ones that tended to break already broke and were thrown away. It seems like 1978 is missing some survivors, mysteriously. Perhaps they were used as upgrades/replacements for 1976-77 thin-mount ones that broke. You can see from this sub-population that early carburetors were center mount, and late ones were side mount, and in between was both.

 

 

 

Dellorto SHA 14/xx, 15/xx

December 24, 2014

 

Dellorto SHA is a family of Italian moped or mini-bike carburetors. SHA’s have flat throttle slides and no jet needles. They all have the same outer size and main body appearance, with a 59mm round flange for an air filter. They have been produced for in Italy from the 1960’s to the 2000’s. In particular the Dellorto SHA 14/12 and 14/9 carburetors were on tens of thousands of US mopeds from 1976 to 1985.

Carburetor Size: The venturi is where the air mixes with gasoline. It is also where the air passage gets narrower, to cause a higher air speed in order to atomize or break up the liquid fuel into smaller droplets. With Dellorto SHA carburetors, two numbers are used to describe the size of the venturi. The first number is the venturi exit, and the second number is the venturi entrance. So looking at an SHA 14/12 from the front you see a 12mm hole, and from the back (engine side) you see a 14mm hole.

Choke Type: The choke is a lever you push or pull, “on” for cold starting, or “off” for normal running. There are three types used on Dellorto SHA carburetors:

A  direct lever  push down lever on carb to put choke “on”, give full throttle to release it “off”
B  linkage lever  same operation as direct lever
C  cable choke  cable goes to a handlebar thumb lever, pull to put choke “on”, let go for “off”  

 

Cable choke is needed when the carburetor choke lever cannot be reached by hand.

Arbeo-Dellorto SHA carbs were made in Spain under license for the Spanish moped Derbi. They were more goldish colored, and tended to leak fuel past the float seat.

Generic SHA: Since the 2000’s there are China made remakes. Most have different screw threads, not Italian-metric. Many have M5-0.80 jet threads, different from Dellorto M5-0.75. The Runtong remake carb has M5-0.75 jet threads. So it can take any Dellorto M5 jet, but many other generics cannot.

 

Original Carburetors

’60-85 Dellorto SHA 14/9 has a lever choke,
20 mm clamp, 16 or 18 sleeve, jet 44, 46 or 48.
Original on 20-25 mph models.

’60-85 Dellorto SHA 14/12 has a lever choke,
20 mm clamp, 16 or 18 sleeve, jet 48, 50 or 52.
Original on 25-30 mph models.

’85-06 Dellorto SHA 14/12P has a linkage choke,
21 mm clamp, 18 sleeve, jet 51 or 53.
Original on 25-30 mph ’85-06 Tomos.

’75-86 Arbeo SHA 12/12 has a lever choke,
20 mm clamp, 18 sleeve, jet 52. Spain 14/12
Original on ’75-86 Derbi models.

’86-90 Arbeo SHA 12/12C has a cable choke,
20 mm clamp, 18 sleeve, jet 54. Spain 14/12C
Original on ’86-90 Derbi models.

 

Replacement Carburetors for Sale


Dellorto SHA 14/12L has a lever choke,
21 mm clamp, 18 sleeve, jet 57, air cover #39
Genuine replacement for SHA 14/12.
Can replace carbs that clamp to 16-19 mm intakes.
$73.0 with 16, 17, or 19 sleeve,  $70.0 with 18 sleeve


Dellorto SHA 14/14R has a cable choke,
19 mm clamp, no sleeve, jet 54, air cover #38d
Replaces Gurtner Motobecane AR2 side-mount.
$85 with choke and throttle cable inner wires


Dellorto SHA 15/15C has a cable choke,
21 mm clamp, 18 sleeve, jet 70, air cover #39
Can replace carbs that clamp to 16-19 mm intakes.
$73 with 16, 17, or 19 sleeve,  $70 with 18 sleeve

 

Clamp size: These new replacement carburetors only clamp tight when the intake pipe is exactly the right size. Many intakes are made slightly smaller or become smaller from wear. When the clamp screw is tightened fully, the carburetor can still move, and eventually slip off. For a 18 sleeve, a 18.00 to 18.10 pipe would clamp tight, but 17.95 or less pipe would not clamp tight. That is not very much forgiveness.

Cut up a can: A strip cut out from an aluminum can, with scissors, can be placed under the sleeve. Thickness is 0.1mm. Either a 1/3 circle or a full circle can be used, as needed. A full circle adds 0.2 to the clamp diameter, for a 17.80 to become 18.00. A 1/3 circle adds 0.1 mm, for a 17.90 to become 18.00. A thin aluminum baking pan is thinner than a can. A thinner full circle is better for when only a little is needed.

Most brand new original Garelli, Minarelli, and Tomos intake manifolds (pipes) are 18.00. But some are 17.95, and actually need a 1/3 strip of aluminum can inserted in order to clamp tight and proper, with new original carburetors.

Cable pipes are for redirecting the throttle cable. Pipe thread is M6-0.75. Adjuster thread is M5-0.75. A throttle cable end can pass through, except 2d. Bikes with front carburetors don’t need them, because the cable goes straight up. Others have gas tanks or floor boards that the cable must go under or around.

a
Although some are shown with adjusters, cable pipes do not include #3a pipe adjuster and #3 pipe lock nut.

 

                 P A R T S    L I S T

price colors mean used  new  new
part# colors mean Dellorto, Minarelli, Tomos, other

pic#  price  part#    description
1    $2.00 1476   rubber boot long
1a  $2.00 1476A 219624 rubber boot short
2    $5.00 1104   top adjuster with nut A13 M6-0.75
2a  $13.0 7423   cable pipe Vespa   22×30 90º use 2ar
2ar $6.00 7423r  cable pipe Vespa   22×30 90º 
2b  none  3698   cable pipe 6560    20×28 90º use 2br
2br $16.0 3698r  cable pipe xxxx    20×30 90º
2c  $13.0 3600   cable pipe 6680    long 70º use 2cr
2cr $8.00 243152 cab. pipe Tomos  long 70º 
2d  $7.00 pipe2d cable pipe Derbi   long 70º no adj.
2e  $7.00 80210400 c. pipe Garelli  medium 35º 
2f    $15.0 163515835  pipe GarVIP short 45º
2g  $5.00 pipe2g cable pipe xxxxx  30×27 90º
2h  $5.00 219623 cab. pipe T. A35  med. 70º 
2j   $5.00 pipe2j cable pipe xxxx    med. 32º
2k  none  10854 cable pipe  xxxx    long 50º
2n  none  pipe2n cable pipe xxxx    long 40º
2as $9.00 53036 cable pipe set 1+2ar+a
2cs $14.0 53037 cable pipe set 1+2h+2cr+3a
2ks none  53038 cable pipe set 1+2k+3a 
2js  none  53073 cable pipe set 1a+2j+3a  
2gs $9.00 53040 11630cu   set 1+2g+3a
2fs  none  265146 Malossi   set 1a+2fr     
2ns none  53058 cable pipe set 2n+3b      
3    $3.00 1691   cable pipe nut M6-0.75  special     
3a  $6.00 219625 pipe adjuster with nut M5-0.75
3b  $3.00 1692   pipe adjuster lock nut M5-0.75

pic# part#  price   description
4   3318    $2.00 top screw M4-0.75 x 14 slot not M4-0.7
5   5011    $1.50 narrow washer M4 
6   6110M  $5.00 6320 top bare metal
6a 6110    $5.00 top bare white plastic
6b 6110    none  top bare black plastic
6c 219596 $21.0 top assy black angled 30° 85-06 Tomos
6d top6d   $15.0 top assy metal   6+7+8+9+10
6e top6e   $15.0 top assy white  6a+7+8+9+10
6f  13662  none  top assy black  6b+7+8+9+10
7   6115    $2.00 6510 hinge pin (in top)
8   6259    $2.00 6460 spring choke (in top)
9   6112    $5.00 6450 lever choke trigger


10   6111 00 $4.00 6410 gasket for carb top
11   3346 00 $10.0 6480 spring throttle return
12   6108/64 $12.0 6590 slide throttle #1 metal 219580 25mph
12a 6108/2x $8.00 slide throttle #2 metal 20mph
12b 6108 00 none  slide throttle #12 plastic


13   4190 0  $5.00 6620 screw M5-0.75 x 15 not regular metric
14   3385 0  $1.50 seal washer 5 x 9 for metal banjo not plastic
15   6106 0  $8.00 6530 banjo metal angled out 3/16″
15a 219584 $9.00 banjo inlet metal straight 3/16″
15b 9249 0  $7.00 6535 banjo plastic angled out 3/16″
15c Der15c  none  banjo inlet thick 1/4″ put a thin hose over 15a
16   6109 0  $5.00 6360 filter fuel plastic mesh
17   6304 0  $2.50 6350 nut M6 teardrop most have regular nut
18   6159 0  $3.00 6420 gasket for air filter
19   6105 0  $3.00 6470 spring for choke plate


20   6112    $7.00 choke plate-lever short  type A lever choke
20a 6114    $7.00 choke plate-lever short
20b 7406    none  6580 choke plate-lever long-bent
20c 8026    $7.00 6570 choke plate-lever long   Cimatti type
21   5417    $3.00 6520 pivot step-bolt choke
22   8773    $2.00 hinge pin 6500 Ø2.0 x 16.5 
23a 14148  $7.00 21-16 sleeve, inner lip for 16.00 mm intakes
23b 12914  $7.00 21-17 sleeve, inner lip for 17.00 MB (some)
23c 10811  $7.00 21-18 sleeve, inner lip for 18.00 mm intakes
23d 11362  $7.00 21-18 sleeve, outer lip for 18.00 mm intakes
23e 227324 $5.00 rubber ring,  for 23d  21 x 16 x 3.5 angled
23e 227324 $0.00 only for carbs that have sleeve 23d Tomos
23f  10146  $7.00 21-19 sleeve, inner lip for 19.00 Peugeot, MB
23g 2300    $7.00 21-19 sleeve, outer lip for 19.00 Peugeot, MB
23h 6124    $5.00 20-16 sleeve, inner lip for 16.00 Morini MO1,
23h cont     Demm, Benelli G2, Tomos ’74-85, Batavus M48
23i  6448    $7.00 20-18 sleeve, inner lip for 18.00 Minarelli V1,
23i  cont     Garelli, Tomos ’85-06, Morini M1
23j    19-17 $22.0 19-17 sleeve, inner lip for Motobecane (some)
23k 114482 $12.0 18-16 sleeve, inner lip for Vespa type SHA
24   6305    $2.00 clamp bolt M6-1.00
25   6140    $4.00 idle screw M4-0.70 x 25 regular metric !
26   3606    $2.00 spring idle Ø4 Ø6 x 12


27   2838    $10.0 float needle valve L=17.0

28 jet M5-0.75 thread
Left is genuine, right is aftermarket. The sizes do not agree.
See Dellorto Jets. These are all genuine jets with the INC logo.
28 1486/42 $5.00 jet 42 0.0178″=0.451
28 1486/43 none   jet 43 0.0182″=0.462 pre-78 Ciao & Bravo
28 1486/44 $5.00 jet 44 0.0186″=0.472
28 1486/45 none   jet 45 0.0190″=0.483 78-on Ciao & Bravo
28 1486/46 $5.00 jet 46 0.0194″=0.493
28 1486/47 $7.00 jet 47 0.0198″=0.503
28 1486/48 $5.00 jet 48 0.0202″=0.513 most 20mph mopeds
28 1486/49 $7.00 jet 49 0.0207″=0.525 78-on Vespa Grande
28 1486/50 $5.00 jet 50 0.0210″=0.533 76-80 Garelli (some)
28 1486/51 $7.00 jet 51 0.0215″=0.546 85-91 Tomos late A3
28 1486/52 $5.00 jet 52 0.0219″=0.556 most 30mph mopeds
28 1486/53 $7.00 jet 53 0.0223″=0.566 92-95 Tomos early A35
28 1486/54 $5.00 jet 54 0.0227″=0.577 86-90 Derbi (flat reed)
28 1486/55 none   jet 55 0.0231″=0.587
28 1486/56 $5.00 jet 56 0.0235″=0.597 96-06 Tomos late A35
28 1486/58 $5.00 jet 58 0.0242″=0.615
28 1486/60 $5.00 jet 60 0.0247″=0.627 96-06 Tomos+exhaust
29 6122-80 $18.0  float all white plastic
30 6123-00 $2.00 float gasket ring all new ones are round
31 6107-96 $5.00 float bowl metal
31 13412 0 $5.00 float bowl plastic          
32 3598-36 $4.00 float bowl screw M4-0.75 x 18  not regular metric


33 4611-50 $4.00 cover clamp ∅60 replica with screw
34 4617-36 none  clamp screw M4-0.75 re-thread nut to use #8-32
35   6117   $9.00 air filter metal screen
00x 0 ∅58 id air covers  TL# bare says   color  holes
36   7758   none  cover #0 assy 00 000 black 2-∅10 with #40 tubes
36   7204   none  cover #0 bare 00 000 black 2-∅10, no tubes
36   9887   $10.0 cover #1 bare 00 000 black 2-∅12, no tubes
37   8602   none  cover #7 bare S33 00 black 2-∅12, no tubes
37   0000   none  cover #0 bare S33 00 grey  2-∅12, no tubes
37a 8603   $11.0 cover #5 bare S3 F44 black 2-∅12, no tubes
37a 0000   none  cover #0 bare S3 F44 grey  2-∅12, no tubes
37a 10574 none  cover #0  bare 00 000 black 3-∅12, no tubes
37b 8632   none  cover #0  bare 00 000 black 2-∅12, no tubes
38   5660   $32.0 cover #0  bare S1 Min gray  2-
38   5660   $25.0 cover-clamp S4 S1 Min gray  2-
38   5660M $15.0 cover-clamp S4 S1 Min black 2-
38a 5346   $12.0 cover #3 bare F27 00 black 2-∅12, no tubes
38b 5199   none  cover #0 bare 10236  black 2-∅12, no tubes
38c 9723   none  cover #6 bare Garelli  black 2-∅10, no tubes
38d 53056 $21.0 cover #4 assy F51 00 black 2-∅12 with #41 tubes
38e 12971 none  cover #2 bare F49  00 black
39   53051 $17.0 air cap, clip, screen set
39a 6183   $10.0 air cap only ∅58 ID
39b 6235   $6.00 clip only
40   7195   $7.00 air inlet tube small Ø8 Ø10 x 20
41   5309   $8.00 air inlet tube large Ø9 Ø12 x 50

42
42    060420 $22.0 air filter, fits 96-06 Tomos, needs a bigger jet
43C  53057   $8.00 cable choke plate set type C  43a+43b+21
43a  plate43  $6.00 cable choke plate only  type C
43b spring43 $3.00 cable choke spring only
44B  223025 $7.00 pivot shaft w/linkage  type B, gets rounded
45B  223027 $2.00 spring for pivot shaft  type B 
46B  223026 none  choke plate xxxxxxx type B
47B  223028 $7.00 choke lever external B, gets hourglass-shaped
48B  031930 $1.00 lock washer M4  B, better to weld 46,47,49
49B  031073 $1.00 nut M4-0.70      B, better to weld 46,47,49

a
50 gset50 $7.00 gasket set SHA14   10, 14, 30
51  52533 $10.0 gasket set pre-’85  10, 14, 30, 18, 18, 1a, 55, 56
51  52533 $10.0 for older SHA14 pre-1985 with 20mm clamp size
52  52579 $12.0 gasket set post-85 10, 14, 30, 18, 23e, 23e, 57
52  52579 $12.0 for newer SHA14 1985-on with 21mm clamp size

55  ring55 $2.00 square rubber ring 14 x 20 x 2.0 for some pre-85
55  ring55 $2.00 only for 20mm intakes (when no sleeve is installed)
56  ring56 $1.00 tiny rubber o-ring  3 x 6.5 x 1.75 only for  ?
57  ring57 $2.00 square rubber ring 15 x 21 x 2.0 for some post-85
57  0-ring57 $2.00 only for 21mm intakes (when no sleeve is installed)


Tomos 85-95 A3+A35
51 219374 $10.0 junction sleeve center mount
52 219373 $19.0 air box bare (silencer)
Tomos 85-91 A3  (pre-85 was Encarwi Ø9 intake)
53 214330 $12.0 intake tube Ø12.5 x 60 straight
60 025195 $1.00 intake screw M6x30 hex
61 026289 $1.00 intake screw M6x18 hex
62 031932 $0.20 washer M6
63 219371 $53.0 center intake A3
63 219564 $53.0 center intake A3 (oil inject)
64 219372 $5.00 intake gasket thin
Tomos 92-95 A35
53 223606 $9.00 inlet tube Ø12.5×110 curved
65 026566 $1.50 intake screw M5x20 allen
66 031931 $0.20 washer 5mm
67 227592 N/A     center intake A35 (oil inject)
Tomos 96-06 A35
55 229705 $14.0 junction sleeve side mount
56 229706 $2.50 inlet grommet
57 229769 $35.0 air box assy 57, 58, 59
58 044438 $1.00 air box screw
59 229704 $7.00 air filter foam
68 223748 $3.00 reed valve gasket
69 222238 $34.0 reed valve 2-petal
70 229707 N/A     side intake (no oil inject.)
71 229716 $21.0 side intake (oil injection)

An oil-injection intake has a M6-threaded hole for the oil line. A no-oil injection intake does not.
Plug the hole with a M6x8 bolt and M6 seal washer, to convert oil-injection to no oil injection. 

 

 

 

 

Encarwi Parts

October 25, 2014

encarwi

Contents:
1. A-type on Tomos
2. S-type on Batavus, others
3. H-type on Trac, others

 

 

 

Part# colors:  Tomos, Laura, Batavus, Trac, other

1. Encarwi A-type: A11, A21, A22
    A83, 88A85/102, 88A85/103

 

– On some early-70’s Laura M48 engines.
– and ’74-85 Tomos A3 mopeds.
– Serviceable from sides.
– No choke cable. Choke is part of throttle.

  #   part#    price    Encarwi A-type on Laura M48 .
00 481780 none  carburetor A11  ∅8? 1970?-
00 slide ∅14? 408, jet M3.5 52-54 M48-01 40kmh
00 481788 none  carburetor A21  ∅12 1972?-
00 slide ∅14 202, jet M3.5 56-58 M48-02 50kmh
00 481789 none  carburetor A22  ∅8? 1972?-
00 slide ∅14? 108, jet M3.5 50-52 M48-03 30kmh
  #   part#    price    Encarwi A-type on Tomos A3 .
00 209070 none  carburetor A83  ∅12 1974-76
00 slide ∅14 426, jet M3.5×15 46 Tomos A3 20,25,30
00 209070 none  carburetor A83  ∅12 1977-83
00 slide ∅14 426, jet M3.5 x 6 46 Tomos A3 20,25,30
00 209070 none  carb 88A85/102 ∅12 1980-84
00 slide ∅14 426, jet M3.5 x 6 46 Tomos A3 20,25,30
00 209616 none  carb 88A85/103 ∅12 1984-85
00 slide ∅14 426, jet M4.0 x 7 50 Tomos A3 20,25,30
01 long jets, thread 3.5, head 12, length 15:
01 481723 $12.0 orig. long jet =Bing45 0.434 mm
01 481724 $15.0 orig. long jet =Bing46 0.445 mm
02 481731 $20.0 long holder for long Encarwi 3.5 jet
03 short jets, thread 3.5, head 3, length 6:
03 209116 $18.0 orig short jet =Bing46 0.445
04 206765 $41.0 long holder for short Bing jet
06 209118 $18.0 slide Ø14 426 with hole, auto-choke
07 209003 $5.00 spring Ø9.5 x 42
08 206763 $34.0 carb top screw-on    M18x1 thread
11 206770 $35.0 float with needle       used only
12 206772 $25.0 float top with seat     new
13 206771 $6.00 gasket for float top    
14 206773 $15.0 banjo black plastic    breaks easy
14 mbanjo $12.0 banjo metal upgrade w/2 washers 
16 206775 $7.00 banjo bolt
17 206774 $15.0 fuel filter all metal    clean & reuse
18 027053 $1.30 screw M4 x 10 slot
20 027079 $5.00 clamp bolt                  
24 200384 none  air filter metal mesh
25 209215 $20.0 air box (silencer)        
26 209216 $27.0 junction sleeve rubber, gets hard
27 209217 $3.00 inlet tube connector
28 209579 $3.00 inlet tube (not shown)  
30 200382  intake gasket thick      
32 217315 none  intake manifold oil inj w/M6x1 hole
33 209085 $22.0 intake manifold           OD 16, ID 12
34 031932 $0.25 lock washer M6       
35 044284 $1.40 hex bolt M6 x 22

 

Encarwi Tomos Carbs

Left, 1974-83 Tomos carb, Encarwi A83, bare.
The jet and jet holder unscrew from the side hole.
The jet can be cleaned out easy, on the roadside.
Right, 84-86 Tomos, Encarwi 88A85/103, complete.
The side hole is blocked. Jet access is from bottom.
The engine must be lowered to access the jet.
Jetting/servicing is ten times more difficult. 

 

Here is a 88A85/103 with the non-removable jet-holder-spray-tube removed. The #50 jet is a 4mm thread, not 3.5 like all the other Encarwi jets. This one was not a tight fit and needed epoxy to hold it. When the jet was unscrewed the whole brass tube turned.

 

 

2. Encarwi S-type
    S8A, S22, S23, S23A, S23B, 88S23/103,
    S25, 88S25/101, S33, S33A

 

– On some early-70’s Laura M48 engines
– and 1974-80 Batavus, 1977-78 Badger.
– Located behind and below engine.
– Needs longer throttle and choke cables.

 

  #    part#   price    Encarwi S-type on Laura M48
00 487180  none  carburetor S22  ∅12  30mph ’72-77
00 slide ∅14 405, jet M3.5×15 54-58, inlet ∅16 45-50kmh 
00 541780  none  carburetor S25  ∅12  30mph ’77-78
00 slide ∅14 167, jet M3.5 x 6 56-58, inlet ∅16 45-50kmh 
00 541780  none  carb 88S25/101 ∅12 30mph ’78-80
00 slide ∅14 188, jet M3.5 x 6 56-56, air inlet ∅16 50kmh
00 481790  none  carburetor S8A    ∅8  25mph ’72-80
00 slide ∅14 190, jet M3.5×15 52-54, air inlet ∅14 40kmh
00 486795  none  carburetor S23A  ∅8  20mph ’75-80
00 slide ∅14 190, jet M3.5 x 6 50-52, air inlet ∅14 30kmh
00 481795  none  carburetor S23B  ∅8  00mph ’75-on
00 slide ∅14 190, jet M3.5 x 6 52-54, air inlet ∅14 25kmh
00 481795  none  carburetor S23    ∅8  00mph ’72-75?
00 slide ∅14 190, jet M3.5×15 50-52, air inlet ∅14 30kmh
00 486785  none  carb 88S23/103   ∅8  00mph ’77-on
00 slide ∅14 190, jet with holder 54, air inlet ∅14 20kmh
  #    part#   price    Encarwi S-type on Flandria
00 000000  none  carburetor S33  ∅12  00mph ’72-77
00 slide ∅14 000, jet M3.5×15 52-54, inlet ∅00 40kmh
00 000000  none  carburetor S33A  ∅12  25/30 ’76-77
00 slide ∅14 000, jet M3.5 x 6 52-54, inlet ∅00 40kmh 
01 long jets, thread 3.5, head 12, length 15:
01 481723 $12.0 orig. long jet =Bing45 0.434 mm
01 481724 $15.0 orig. long jet =Bing46 0.445 mm
01 481726 none  orig. long jet =Bing50 0.478 mm
01 481727 none  orig. long jet =Bing52 0.493 25mph
01 481729 none  orig. long jet =Bing56 0.523 30mph
01 481730 $7.00 orig. long jet =Bing58 0.541 mm 
02 481731 $20.0 long holder for long Encarwi jet
03 short jets, thread 3.5, head 3, length 6:
03 486750   none orig. short jet =Bing50 0.478 20mph
03 bing51g $4.00 generic48 jet ≈Bing51 0.480 mm
03 bing52g   none generic49 jet ≈Bing52 0.490 mm
03 486752 $5.00 orig. short jet =Bing52 0.493 25mph
03 bing53g $4.00 generic50 jet ≈Bing53 0.500 mm
03 486754 $5.00 orig. short jet =Bing54 0.508
03 bing56g $4.00 generic52 jet ≈Bing56 0.520 mm
03 486756 $11.0 orig. short jet =Bing56 0.523 30mph
04 481722 $41.0 long holder for short Bing jet
06 481758 none  throttle slide #405  S22 30mph
06 561742 $35.0 throttle slide #167  S25 30mph
06 5617xx  none  throttle slide #188  88S25/101 
06 486723 none  throttle slide #190  25 & 20mph
07 481722 $5.00 spring Ø9.5 x 42
08 481721 $34.0 carb top screw-on    M18x1 thread
09 481746 $7.00 idle screw M4-0.7    can use M4
10 481747 $3.00 idle screw spring Ø4.6 Ø6.6 x 9 
11 481736 $35.0 float with needle         used only
12 481738 $25.0 float top with seat      
13 481737 $6.00 gasket for float top    
14 481740 $15.0 banjo black plastic     
14 mbanjo $12.0 banjo metal upgrade w/2 washers 
16 481742 $7.00 banjo bolt
17 481741 $15.0 fuel filter
18 481739 $1.30 screw M4 x 10 slot  
20 481724 $5.00 clamp bolt
21 481743  $7.00 choke plate
22 481745 $3.00 bolt choke pivot          
23 481744 $3.00 spring choke               
24 481732 none  air filter metal mesh
25 481713 none  air box (13.5id, 16od)  N/A 30mph
25 481734 none  air box (11.5id, 14od) N/A 25/20mph
26 481733 none  rubber band              N/A
27 481735 $8.00 wire clip                     
28 481793 none  intake tube 16 id    N/A  30mph
28 486781 $5.00 intake tube 14 id      25 & 20mph

 

Left 1970’s original float, right 90’s replacement

 

 

 

3. Encarwi H-type: H12, H8 

 

– Made special for Laura M56 engine.
– Serviceable without removal.
– Used on 1978-80 Batavus Regency (M56)
– 1981-85 Trac Clipper, Eagle, Hawk (M56)

 # qty  part#  price    Encarwi H-type 1978-85
116 1 561782 $220. carburetor H12 ∅12 30, 25mph
116 1 561782 $000.  slide ∅14, jet M3.5 56 .
116 1 561787  N/A    carburetor H8    ∅8  20mph
116 1 561787 $000.  slide ∅12?, jet M3.5 46 .
118 1 481736 $35.0 =206770 float with needle, good-used
119 1 481737 $6.00 =206771 gasket for float top
120 1 561741 $35.0 float top and seat no vent use 206772
120 1 206772 $25.0 float top and seat vented
121 3 481739  =027053 screw M4 x 15 slot
122 1 mbanjo $12.0 banjo metal with 2 washers
122 2 swash8 $1.00 banjo seal washer 8mm
123 1 481741 $15.0 =206774 fuel filter
124 1 481742 $7.00 =206775 banjo bolt
125 1 561740 $5.00 idle screw M5-0.80 x 16
126 1 481747 $2.00 spring idle screw Ø5,Ø7 x 10
127 1 082510 $40.0 short holder for short Bing jet 
127 1 491722 $30.0 short holder for medium Encarwi jet 
128 short jets, thread 3.5, head 3, length 6:
128 1 486746 $18.0 orig. short jet #46 =0.445 mm
128 1 486756 $11.0 orig. short jet #56 =0.523 mm
128 1 486756 $4.00 generic subst #52 =0.520 mm
128 1 486756 none  generic subst #53 =0.530 mm
128 medium jets, thread 3.5, head 8, length 11:
128 1 566756 $12.0 orig medium jet 56 =0.523 mm
128 1 566746  N/A    orig medium jet 46 =0.445 mm
129 1 561748 $25.0 slide throttle Ø14 (H12) #3
129 1 561742  N/A    slide throttle Ø12? (H8)
130 1 046430 $7.00 rubber cover over carb top
131 1 561721 $25.0 carb top white plastic
132 2 561745 $2.00 o-ring for choke 1 x 4.0
133 1 561743  N/A    choke slide
134 1 561743  N/A    choke slide set screw M4
135 1 481759 $10.0 spring throttle Ø9.5 x 44
136 1 491724 $8.00 spring choke return
137 1 561747  choke cable wire only
138 1 561713 $5.00 air filter foam strip
139 2 561714  N/A    air filter screen
140 1 561747 $52.0 choke cable assy 132,133,134,136,137
143 1 823514 $0.70 screw M5 x 30 phillips
144 1 561795  N/A    air box with filter good used

 

Encarwi H12 carb on Trac M56 engine

Encarwi H12, with no top, on Trac M56 engine

 

Encarwi Jets: Most Encarwi carburetors use standard Bing 3.5mm jets. Those jets have a “short” head that is only 3mm long. To use a short jet, the jet holder must be for a short jet. But some Encarwi carburetors have longer 3.5mm jets with 8mm “medium” or 12mm “long” heads.

Encarwi jet holders
1  481722 long jet holder for short (Bing) jet 
2  481731 long jet holder for long Encarwi jet  can be a substitute for 3
3  491722 short jet holder for medium Encarwi jet 
4  082510 short jet holder for short (Bing) jet

 

 

 

Bing Jets

October 26, 2011

Bing jets are in Bing and some Encarwi carburetors.

3.5 mm thread (M3.5-0.60) Bing jets are on Puch-Bing, Solo-Bing, Kreidler-Bing, and Encarwi.

4.0 mm thread (M4.0-0.70) Bing jets are on Sachs-Bing, late 80’s AD-Bing and 90’s Korado-Bing.

Myrons Mopeds Bing Jet Sizes Chart

These jets are on other 1970’s – 80’s small engines with Bing carburetors. 

The Bing 3.5 main jets are also idle jets on some bigger Keihin carbs.

The Bing 4.0 main jets are also idle jets on some bigger Dellorto carbs

Original Bing jets are numbered wrong, in a sense. The jet number is not the millimeter size. An original Bing 54 is actually 0.51 mm, not 0.54. This was discovered this in the early 2000’s when aftermarket Bing jets came out. 200 jets were carefully measured with precise wire guages, and then plotted on the graph at right. The original jets (and the first A&R generics) form one line. All other generic jets form a different line.

Generic Bing jets are numbered correctly. The size they say is the millimeters they are. So a generic Bing 54 is actually 0.54 mm.

 

 

 

 

 

 

 

 

 

 

           Bing Jets (3.5 mm) 

 part #   maker   jet#  close to    measured size      price     applications

78drill   custom #00 =Bing48 0.016″ = #78 drill —————————————————————
3.5×44  custom #00 =Bing46 0.0173″=0.440mm  $15.0  soldered, 78-drilled, then filed with .017 guitar string
Bing46  original #46 =Bing46 0.0175″=0.445mm  $18.0  76-83 Tomos early A3 models (30, 25, and 20mph)
3.5×45  custom #00 =Bing47 0.0177″=0.450mm  -N/A–
77drill   custom #00 =Bing48 0.018″ = #77 drill —————————————————————
3.5×46  custom #00 =Bing48 0.0181″=0.460mm  -N/A–
Bing48  original #48 =Bing48 0.0182″=0.462mm  $15.0  78-80 Puch (2-spd hi torque Ø12 carb 20mph)
3.5×47  custom #00 =Bing49 0.0185″=0.470mm  -N/A–
Bing50  original #50 =Bing50 0.0188″=0.478mm    none  76-78 Batavus (Laura M48 Ø8 carb 20mph)
3.5×48  generic #48 =Bing51 0.0190″=0.480mm  $4.00
3.5×49  custom #00 =Bing52 0.0190″=0.490mm  -N/A–
Bing52  original #52 =Bing52 0.0194″=0.493mm  $5.00  76-78 Batavus (Laura M48 Ø8 carb 25 mph)
3.5×50  generic #50 =Bing53 0.0195″=0.500mm  $4.00
76drill   custom #00 =Bing48 0.020″ = #76 drill —————————————————————
Bing54  original #54 =Bing54 0.0200″=0.508mm  $5.00  74-83 Puch (1-spd alum. cylinder, Ø12 carb 2.22, 20mph)
3.5×51  generic #51 =Bing54 0.0201″=0.510mm 
3.5×52  generic #52 =Bing55 0.0204″=0.520mm  $4.00
Bing56  original #56 =Bing56 0.0206″=0.523mm  $11.0  77-80 Batavus M48 and M56 (30), 80-83 Trac M56 models
3.5×53  generic #53 =Bing56 0.0209″=0.531mm  none 
75drill   custom #00 =Bing48 0.021″ = #75 drill —————————————————————
3.5×54  generic #54 =Bing57 0.0212″=0.540mm  $4.00
Bing58  original #58 =Bing58 0.0213″=0.541mm  $10.0  78-83 Puch (2-spd hi torque cyl. Ø12 carb 2.22 30mph)
3.5×55  generic #55 =Bing59 0.0217″=0.551mm  $4.00
3.5×56  generic #56 =Bing60 0.0220″=0.561mm  $4.00
Bing60  original #60 =Bing60 0.0222″=0.564mm    none  78-83 Puch (1-spd hi torque cyl. Ø12 carb 2.22 30mph)
3.5×57  generic #57 =Bing61 0.0224″=0.571mm  $4.00
75drill   custom #00 =Bing48 0.0225″=#74 drill —————————————————————
3.5×58  generic #58 =Bing62 0.0228″=0.580mm  $4.00
Bing62  original #62 =Bing62 0.0229″=0.582mm  $7.00
3.5×59  generic #59 =Bing63 0.0232″=0.591mm  $4.00
Bing64  original #64 =Bing64 0.0234″=0.594mm  $6.00  74-83 Puch (1-spd al cyl Ø14 carb 2.22 needle jet 30mph)
3.5×60  generic #60 =Bing64 0.0235″=0.600mm  $4.00
Bing66  original #66 =Bing66 0.0239″=0.607mm    none
75drill   custom #00 =Bing48 0.024″ = #73 drill —————————————————————
3.5×61  generic #61 =Bing65 0.0240″=0.610mm  $4.00
3.5×62  generic #62 =Bing66 0.0244″=0.620mm  $4.00
Bing68  original #68 =Bing68 0.0248″=0.630mm   none   78 Sears (1s al cyl Ø14 carb 30mph), Kreidler (30mph)
3.5×63  generic #63 =Bing68 0.0248″=0.630mm  $4.00
75drill   custom #00 =Bing48 0.025″ = #72 drill —————————————————————
3.5×64  generic #64 =Bing69 0.0252″=0.640mm  $4.00
Bing70  original #70 =Bing70 0.0254″=0.645mm    N/A   84-86 Puch Cobra (Ø14 carb, 2.17 needle jet 25mph)
3.5×65  generic #65 =Bing71 0.0256″=0.650mm  $4.00
75drill   custom #00 =Bing48 0.026″ = #71 drill —————————————————————
3.5×66  generic #66 =Bing72 0.0260″=0.660mm  $4.00
Bing72  original #72 =Bing72 0.0260″=0.660mm    N/A   84-86 Puchs had bigger main jets, but smaller needle jets.
3.5×67  generic #67 =Bing73 0.0264″=0.670mm  $4.00
Bing74  original #74 =Bing74 0.0267″=0.678mm    N/A   1990’s Puch remakes also had 70’s jets, 2.17 needle jets.
3.5×68  generic #68 =Bing74 0.0268″=0.681mm  $4.00
3.5×69  generic #69 =Bing75 0.0272″=0.690mm  $4.00
Bing76  original #76 =Bing76 0.0273″=0.693mm  $6.00
3.5×70  generic #70 =Bing77 0.0278″=0.705mm  $4.00
75drill   custom #00 =Bing48 0.028″ = #70 drill —————————————————————
3.5×71  generic #71 =Bing78 0.0280″=0.715mm  -N/A--
Bing78  original #78 =Bing78 0.0280″=0.711mm    N/A
3.5×72  generic #72 =Bing79 0.0283″=0.725mm  $4.00
Bing80  original #80 =Bing80 0.0285″=0.724mm    N/A
3.5×73  generic #73 =Bing81 0.0287″=0.735mm  none 
3.5×74  generic #74 =Bing82 0.0291″=0.745mm  $4.00
75drill   custom #00 =Bing48 0.0292″ = #69 drill —————————————————————
Bing82  original #82 =Bing82 0.0292″=0.742mm  $7.00 2000’s Bing Ø15 carb with smaller 2.17 needle jet
3.5×75  generic #75 =Bing83 0.0296″=0.755mm  none 
Bing84  original #84 =Bing84 0.0300″=0.762mm  none  1978-79 Puch Magnum X

 

cleaning a #25 jet

       Bing Jets (4.0 mm) 

At right, the smallest of the small. The #25 pilot jet is bigger than wire wheel wires, but smaller than wire brush wires in the background. It’s three hairs wide!

part number  maker  jet#  close to    measured size      price     applications

Tomos243222 Dell.  #25 =Bing27 0.0107″=0.272mm     $8  Tomos A55 pilot (idle) jet
Tomos243110 Dell.  #29 =Bing31 0.0124″=0.314mm     $8   same as Tomos #25 idle jet “cleaned” with #80 drill
D1486-030 Dellorto #30 =Bing33 0.0128″=0.325mm     $8  good for A55 pilot jet, mix screw 1 turn more out
77drill   custom #00 =Bing48 0.0135″ = #80 drill —————————————————————
D1486-032 Dellorto #32 =Bing35 0.014″ = 0.355mm     $8  same as drilled with #80 drill, sub for A55 pilot jet
77drill   custom #00 =Bing48 0.0145″ = #79 drill —————————————————————
D1486-035 Dellorto #35 =Bing39 0.0149″=0.378mm    N/A
77drill   custom #00 =Bing48 0.016″ = #78 drill —————————————————————
D1486-040 Dellorto #40 =Bing45 0.0170″=0.431mm     $8
4mBing45 Bing orig #45 =Bing45 0.0171″=0.434mm    N/A   Sachs 504/1A DK (19mph)
77drill   custom #00 =Bing48 0.018″ = #77 drill —————————————————————
4mBing48 Bing orig #48 =Bing48 0.018″ = 0.46mm      $8
D1486-043 Dellorto #43 =Bing49 0.0182″=0.462mm    N/A
4mBing50 Bing orig #50 =Bing50 0.0183″=0.465mm     $8  Sachs 504/1B and 505/1B (Ø10 carb 20mph)
D1486-044 Dellorto #44 =Bing51 0.0187″=0.475mm    N/A
4.0×48 000 generic #48 =Bing51 0.0189″=0.480mm
D1486-045 Dellorto #45 =Bing51 0.0190″=0.483mm     $8
4mBing52 Bing orig #52 =Bing52 0.0194″=0.493mm    $8.00 Sachs 504/1A and 505/1A (Ø12 carb 30mph)
D1486-046 Dellorto #46 =Bing52 0.0194″=0.493mm    N/A
4.0×50 000 generic #50 =Bing53 0.0197″=0.500mm
76drill   custom #00 =Bing48 0.020″ = #76 drill —————————————————————
4mBing54 Bing orig #54 =Bing54 0.0200″=0.508mm    $8  ’84-86 Puch Austro Daimler (30mph)
D1486-047 Dellorto #47 =Bing54 0.0198″=0.503mm    N/A
D1486-048 Dellorto #48 =Bing55 0.0202″=0.513mm    $8  Sachs 504/1A and 505/1A (without air filter box)
4.0×52 000 generic #52 =Bing56 0.0205″=0.520mm
4mBing56 Bing orig #56 =Bing56 0.0206″=0.523mm    N/A  
D1486-049 Dellorto #49 =Bing56 0.0207″=0.526mm    N/A
75drill   custom #00 =Bing48 0.021″ = #75 drill —————————————————————
D1486-050 Dellorto #50 =Bing57 0.0210″=0.533mm    N/A
4.0×54 000 generic #54 =Bing58 0.0212″=0.540mm
4mBing58 Bing orig #58 =Bing58 0.0213″=0.541mm   $8.00 Sachs 504/1D and 505/1D (Ø12 D-carb 30mph)
D1486-051 Dellorto #51 =Bing59 0.0215″=0.546mm    N/A
4.0×56 000 generic #56 =Bing51 0.0220″=0.560mm
75drill   custom #00 =Bing48 0.0225″=#74 drill —————————————————————
D1486-055 Dellorto #55 =Bing63 0.0230″=0.580mm     $8
4.0×58 000 generic #58 =Bing63 0.0230″=0.580mm
4.0×60 000 generic #60 =Bing65 0.0236″=0.600mm
75drill   custom #00 =Bing48 0.024″ = #73 drill —————————————————————
4.0×62 000 generic #62 =Bing68 0.0244″=0.620mm
D1486-060 Dellorto #60 =Bing69 0.0250″=0.635mm     $8

 

 

 

Bing Carburetor Service

May 3, 2008

Bing VergaserContents:

1. Carb Elbows: Long and Short

2. Exploded View and Parts Names

3. Carburetor Service Info Sheet

4. Float Needles: Rubber tip and Metal tip

4. Floats

6. Fuel Mixture is Controlled by Five Things

 

1. Carb Elbows Long and Short

Sachs Bings can have long or short cable elbows.

Puch Bings can have long or short cable elbows.

 

 

 

 

 

 

 

 

 

 

Sachs Bing Cable Elbows: Left photo above, left is the long carb elbow, used on KTM Foxi, Sparta Buddy, and most Sparta Foxi models. Right, is the short carb elbow used on other Sachs engine models. The Sachs elbows are 7mm, not 6mm threads like Puch ones. The bigger elbow allows the throttle cable small end to pass through the 6mm adjuster. So Sachs double-ended throttle cables do not come with adjusters. The adjuster stays with the elbow. Puch Bings have 6mm elbow threads, and 5mm adjuster threads, too small for the cable end to pass through. So Puch double ended throttle cables have the 5mm adjuster trapped in them.    

Puch Bing Cable Elbows: Right photo above, left is the long carb elbow, used on Maxi models, also with the black choke extension. Right, is the short carb elbow used on Magnum type models. The current aftermarket “Puch” throttle cables are made for the short carb elbow. They idle way fast if used with the long elbow, because the slide is not allowed to go fully down to idle. Myrons sells a long elbow throttle cable, for Puch Maxi, made from a modified “Puch” throttle cable. The wire needs to be about 12mm longer. The long elbow comes on Maxi type sheet metal frame models. The short elbow comes on Magnum type tube frames, such as Sears Free Spirit or JC Penney Pinto. The short elbow is so your foot does not hit it when you get on and off the bike. See the exploded view diagram below. Other Bing moped (under 15mm venturi) carburetors are the Sachs Bing, Kreidler Bing, Solo Bing, Tomos Encarwi, Batavus Encarwi, Trac Encarwi. Much bigger Bing carburetors are also on BMW, KTM, Penton, Sachs, Maico, DKW motorcycles, all made in or near Germany.

 

2. Exploded View and Parts Names

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. Carburetor Service Info Sheet

Below, the choke slide and throttle slide must be installed simultaneously. It is difficult. The throttle slide has a slot that must line up with a prong in the carb body. The top of the choke slide slides onto a deep wide notch at the bottom of the choke rod, so moving the choke rod moves the choke slide. It often gets left out or disconnected. When the choke slide is disconnected from the choke rod, the choke will be “on”, blocking off the air supply, whenever the throttle slide is down or closed. Normally when a Puch is given full throttle, the choke slide and rod are lifted all the way up until it clicks. The click is the choke rod clip #24 settling into the clip groove near the middle of the choke rod #23. When the throttle cable is not adjusted tight enough, the choke is not lifted all the way off, and it does not click until you manually reach down and pull up on the choke rod. When the throttle cable is adjusted too tight, the engine races and does not idle slow, even with the idle screw loosened all the way. See also General Carburetor Service and Jetting for how to clean and adjust carbs in general. 

 

White Flakes

These white flakes were the cause of a customer’s Puch not running. By chance a tiny spec broke off and lodged in the main jet.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4. Bing Float Needles 

All “Bing Puch Carbs” have the slotted float type float needle with a rubber cone tip, except for some of the Sears Free Spirit 1/14/163  and 1/14/164 carbs, which have a Sachs Bing type float needle that does not lock into a slot in the float and has a metal cone tip.

 

5. Floats

The original 1970’s floats were white. They weigh 5.6 grams when new. Modern replacements are black. They also weight 5.6 grams. 

After years of exposure, the original white floats gradually absorb ingredients from the fuel and oil. They turn color, first light gold, then gold, then orange-gold, then light brown. The darker the color the more wight they gain, and the less they float.  Orange-gold used floats weigh 5.8 g, light brown ones weigh 5.9, brown ones weigh 6.0 g.

 

6. What part controls mixture depends on how much throttle opening

Slide Carburetors Diagram

 

 

 

 

Jet Drills

January 27, 2007

 

Above, a Tomos A55 idle jet (M4 thread) is physically bigger than a Puch Maxi main jet (M3.5 thread), but the hole size is much smaller. The photo shows how the #25 jet, 0.010" (ten thousandths of an inch), will allow the thinner wire of the wire wheel to pass through the hole, but not the thicker wire of the wire brush. This is a useful cleaning technique.

Above, a Tomos A55 idle jet (M4 thread) is physically bigger than a Puch Maxi main jet (M3.5 thread), but the hole size is much smaller. The photo shows how the #25 jet, 0.011″ (eleven thousandths of an inch), will allow the thinner wire of the wire wheel to pass through the hole, but not the thicker wire of the wire brush. This is a useful cleaning technique.

This will help you visualize how small these drills and jets are!

Moped main jets range from 0.018″ (#77 drill) to 0.026″ (#71 drill). 

Moped idle jets, like Tomos A55, are 0.011″ (smaller than #80).

An average human hair is 0.003″ (three thousandths of an inch).

So moped jet holes are 4 to 9 hairs wide!

Shauns well used jet drill container from the 1980's

Shaun’s well used drill container from 1987

 

Jet Drills: All through the late 1980’s and 1990’s, Shaun (at Royal Cyclery and later at Myrons Mopeds) used the USA-made jet drills to service carburetors. The drill sizes are an American wire gauge. They did not vary in size. Those 20-piece Drill Sets 61 to 80, cost $40 in 2015, $33 in 1998. and $29 in 1987. Some are in clear plastic round dome containers, and some are in conventional metal drill set boxes.

 

 

Drill Set 61-80 USA-made

Drill Set USA-made

Jet Drills made in China

Set 1 China-made

China-made Drills: In the 2000’s there were many China made tools sold in “surplus” tool stores. The China made 20-piece Drill Sets 61 to 80, sell for $7 to $10, or one fourth as much. They have an excellent blue plastic container, that only lets out one at a time. But the drill sizes are all wrong. From about 2010 to 2014, Myrons Mopeds sold these inexpensive drill sets, not knowing that the drill sizes were inexact, to say the least.

So although the China sets cost one forth as much, they only have about seven or eight different sizes, and they lack the smaller sizes below 0.4 (or sometimes 0.6) mm. Each set is different.

 

Jet Drills made in USA

Jet Drills made in USA

Set 2 China-made

Some have poorly made drills, twisted funny, bigger at the cutting end, or lumpy, varying in thickness. Some have poorly made cutting tips, so they might wander, grab and break, or not cut well.

Despite the poor quality and inexactness, the inexpensive drills are still useful for cleaning purposes, but not for measuring and maybe not for drilling. Fortunately, brass carburetor jets are the easiest thing to drill, with a drop of oil and a pilot hole already there.

 

 

Micro Drills and Wires for Sale Individually

These drills are measured at the shank (the smooth part). At the cutting edge they are 1 or 2% bigger.

These wires are steel guitar strings, cut into 5 inch lengths. 

“Metric” jets have a number that literally means hundredths of a millimeter, so a 64 jet is 0.64 mm.

Micro Drills for sale

inch   mm/#  price     moped jets that it cleans
0.011   wire     N/A Gurtner Motobecane diffuser – two idle holes (.013)
0.0135 #80  $6.00
0.0145 #79  $5.00
0.0157 0.40  $3.00 Dellorto 38 (.0162), Bing 42 (.0162)
0.016   #78  $4.00 Dellorto 40 (.0168), Bing 44 (.0167)
0.017   wire  $0.50 Dellorto 42 (.0177), Bing 46 (.0175)
0.018   #77  $3.50 Dellorto 44 (.0186), Bing 50 (.0188)
0.019   ——  $2.00 Dellorto 46 (.0194), Bing 52 (.0194)
0.0197 0.50  $2.00 Dellorto 48 (.0202), Bing 54 (.0200), “Metric” 51 (.0201)
0.0200 #76  $3.50 Dellorto 49 (.0207), Bing 56 (.0206), Gurtner 210=52 (.0210)
0.021   #75  $4.00 Dellorto 51 (.0215), Bing 58 (.0213), Gurtner 220=54 (.0220)
0.0225 #74  $5.00 Dellorto 55 (.0231), Bing 62 (.0229), Gurtner 230=56 (.0230)
0.023   ——  $2.00 Dellorto 56 (.0235), Bing 64 (.0234), Gurtner 240=58 (.0236)
0.0235 0.60  $2.00 Dellorto 58 (.0242), Bing 66 (.0239), Gurtner 245=59 (.0239)
0.0235 0.60  $1.50 Dellorto 58 (.0242), Bing 66 (.0239), Gurtner 250=60 (.0242)
0.024   #73  $3.00 Dellorto 60 (.0247), Bing 68 (.0248), “Metric” 63 (.0248)
0.025   #72  $3.50 Dellorto 62 (.0255), Bing 70 (.0254), “Metric” 65 (.0256)
0.026   #71  $4.50 Dellorto 66 (.0268), Bing 74 (.0267), “Metric” 68 (.0268)
0.0275 0.70 x N/A  Dellorto 70 (.0280), Bing 78 (.0280), “Metric” 71 (.0280)
0.028   #70  $4.00 Dellorto 72 (.0287), Bing 80 (.0287), “Metric” 73 (.0287)
0.0292 #69  $4.50 Dellorto 78 (.0306), Bing 84 (.0301), “Metric” 77 (.0303)
0.030   wire     N/A Dellorto 80 (.0312), “Metric” 79 (.0311), Gurtner K80 (.0311)
0.031   #68  $4.50 Dellorto 82 (.0318), “Metric” 81 (.0319)
0.0315 0.80  $2.00 Dellorto 84 (.0324), “Metric” 82 (.0323)
0.032   #67  $3.00 Dellorto 86 (.0331), “Metric” 84 (.0331)
0.0325  —— $2.00 Dellorto 88 (.0337), “Metric” 86 (.0339)
0.033   #66  $4.50 Dellorto 90 (.0343), “Metric” 88 (.0346)
0.034   wire     N/A “Metric” 90 (.0354)
0.035   #65  $3.00 “Metric” 92 (.0362), Gurtner MB (side mount) diffuser (.0358)
0.0354 0.90  $2.00 “Metric” 94 (.0370)
0.036   #64  $3.00
0.037   #63  $2.50
0.038   #62  $1.50
0.039   #61  $1.50
0.0394 1.00  $1.00

 

Deluxe 40-piece Micro Drill Set

Jet Drills 80-72 and 71-60

Myron’s Mopeds two case deluxe micro drill set, 80 to 72 (small) and 71 to 60 (large) plus many in-between sizes.
Price none, sorry no more.

Slide clear top plastic until hole is over drill (and pointer is on desired drill number). Only lets one drill out at a time. Never take out more than one at a time, or they can get mixed. The case keeps them organized. If any get lost, dull, or broken, individual drills can be bought at some hardware stores for $3-$4 each.

Useful for sizing to tell how big a jet really is (sometimes they’re drilled out or labeled wrong).

Useful for cleaning varnish or corrosion coating the inside of an old jet. It doesn’t really clean out any other way. The drill is used as a file, held with a needlenose pliers.

Useful for drilling jets to make a new size, as an alternative to buying ones. The drill is held with a needlenose pliers, and the jet is rotated with your fingers, with a drop of oil. To go down in size, fill the hole with solder and re-drill it smaller.

 

 

 

Here is a pin vise, a mini drill chuck, price $8

 

 

 

 

 

 

 

Other Tools for Cleaning Jets

Using a micrometer to measure a 0.017 wire

Using a micrometer to measure a 0.017″ wire

Guitar steel string 17 thousandths of an inch

Guitar string

Guitar Steel Strings in the smaller sizes are excellent tools for cleaning small holes. Here is a 0.0170 inch steel wire guitar string, perfect for cleaning out a 1974-85 Tomos stock jet size 46 that has a 0.0175 inch hole. A Honda Express NC50 (Keihin) carburetor, has a long brass idle jet tube with a tiny jet hole at the far end, too far for a drill to reach. For that, only a 2 or 3 inch piece of 0.010″ steel guitar string will reach to clean it. Ultrasonic cleaners, carb spray, or soaking are not effective for that. Other examples are a Sachs 52 jet 0.0190 would be cleaned by a 0.018″ wire, or a Motobecane 230 jet 0.023″ would be cleaned by a 0.022″ wire. The wire has to be a little smaller than the hole. Plain steel strings range from 0.008″  to 0.017″ in steps of 0.001″. Wound strings range from 0.017″ to 0.065″. 

 

Torch Tip Cleaner Set

Torch Tip Cleaner Set

Root Canal Files

Root Canal Files (say ahhh)

Welding Torch Tip Cleaners are another excellent tool for cleaning small holes. The tip has a cutting surface but not the sides. So it is made to clean the hole without widening it.

Wire Feeler Gauge Sets: There are also wire gauge measuring sets that look the same as the torch cleaner set shown.

Dentist’s Root Canal Files are also good for cleaning small holes. Color coded files range from 0.06 to 1.10 mm (0.0024 to 0.0433 inch).