Laura M48 Parts

 

Batavus VA and HS50 (M48) Parts

Batavus (M48)

1. Parts for Laura M48 Engine

The parts list below is made from all three versions (20, 25, 30 mph) of the book at right. For the M48 models, Batavus dealers were given parts books only for their state’s speed version, and not other state’s. So a dealer in 25mph state like Arizona did not know, and could not easily find out, what parts were different in a 30mph state like California. There were just a few pages that were different.

Parts for sale have a price. Green is new, dark green is used. N/A means not available. Many parts are not for sale here, but might be for sale elsewhere. Those item’s prices have a link to click on to get to them. Common things like nuts, bolts, washers, clips, pins, keys, studs, belts, chains, engine hardware, pistons, piston rings, spark plugs, belts, all are listed in their “Parts for Sale by Type” section. Remember the sizes or descriptions given here, when you go there. For example, “nut M10-1.0” has a link to “Engine Hardware” section where you would scroll down to “Engine Nuts” to find that size, 10mm, thread, 1.0mm, height 10mm, and style, regular.

#   part# qty price  description

Batavus M48 Engine 1976 exploded view1.  480201 2 none Batavus decal
2.  480200 2  $19 engine cover
3.  540292 4    $5 rubber tab
4.  820502 2  50¢ hex bolt M5x15
5.  84350010¢ lock washer M5
6.  480981 1  $15 support plate
7.  480980 1  $22 start lever
8.  827500 6  25¢ hex nut M5
9.  843500 6  10¢ lock washer M5
10 480890 1  $12 locking plate
11 480882 1  $60 end plate w/button
12 480824 1  N/A start button
13 480883 1   $8 start spring
14 480889 1  $15 friction plate
15 480683 1  N/A exhaust gasket
16 828010 1   $4 hex nut M10-1.0×6
17 840010 1   $8 tab washer M10
18 480886 1  $25 weight-spring ring
19 810081$10.0 ball bearing 6302 15x35x11
20 820520 6   $5 splined bolt M5x27
21 480881 1  N/A alum. hub w/ steel saucer
21a 00000$35 steel saucer only
22 480887 1   $8 saucer spring  12x28x1.0
23 816180 1  N/A felt oil ring 15x21x3
    substitute  $6.00 oil seal 15x21x3
24 813081$20 needle bearing 15x21x22
25 816480none   oil seal 20x42x7 offset
26 841512 1   $8 crank circlip Ø42×1.75 inner
27 838045 2  N/A dowel roll pin Ø5×12
28 480181 1  N/A case gasket
29 480381 1  $90 crankshaft
30 480325 1  $12 piston bushing Ø11.6x14x11
31 841520 2  link piston pin clip Ø12
32 480501 1  link piston pin Ø12 x 33
33 480580 1  $60 piston assy Ø40×18-12-14
34 480502link piston ring Ø40 x 1.5 FG
35 480682$$6 base gasket
36 829680 4  link cylinder stud M6 x 115
37 847600 4  20¢ plain washer M6
38 84660020¢ lock washer M6
39 827600 4  50¢ hex nut M6 x 6
40 481890 1  link spark plug cap
41 490814 1   $8 clutch washer 15x28x0.5
42 830000 1  link flywheel key 3 x 5mm
43 848011 1  20¢ plain washer M10
44 828000 1  50¢ tooth washer M10
45 828000  $2 nut M10-1.0×10
46 816181 1  $12.0 oil seal 14x30x7
    substitute  $7.00 oil seal 15x30x7

47 823506 6  50¢ case screw M6 x 25?
51 820603 1   50¢ hex bolt M5x??
52 843600 1  20¢ lock washer M5
53 481784 2   $7 inlet gasket
54 481783$38 reed valve 4-petal
55 813086 2  N/A needle bearing Ø16
56 481591 1  N/A pulley dust cover
58 481786 1  N/A dirt splash shield
59 481797 2  N/A step washer M5
60 820500 2  link hex bolt M5
61 480892 1   $8 clutch leaf spring
63 540898 1 $25 pressure plate used
64 485194 1  N/A crankcase (20mph)
64 485180 1  N/A crankcase (25 & 30)
65 480695 1  N/A cylinder head (20 & 25)
65 485695 1  N/A cylinder head (30mph)
66 485697 1  N/A cylinder (20mph)
66 485690 1  N/A cylinder (25 & 30)
67 481883 1   $3 spark plug NGK B5HS
70 480185 1  N/A grommet for wires
71 480894 1  N/A housing-thin-pulley (20)
71 480880 1  150 housing-pulley (25 & 30)
72 486795 1  link  carb. assy 8mm (20mph)
72 481790 1  link  carb assy 8mm (25mph)

72 541780 1  link  carb assy 12mm(30mph)
73 481794 1  N/A intake pipe (20mph) Ø6
73 481785$25 intake pipe (25 & 30) Ø11
74 481594 1  N/A pulley with 11T (20mph)
74 481598$70 pulley with 13T (25 & 30)
75 480893 1  link  v-belt thin long(20mph)
75 480891 1  link  v-belt thick (25 & 30)
76 481091 1  N/A sprocket 11T (20mph)
76 481093 1  N/A sprocket 13T (25 & 30)
77 481506 1  N/A tab nut (20mph)
77 481505 1  N/A tab nut (25 & 30)
79 480899 1   $8 clutch washer (25,30) 12x24x0.5
00 480899a    $5 clutch washer thicker 12x24x0.8

 


Batavus M48 Clutch Small Parts

Batavus M48 Clutch Small Parts

2. M48 Engine Parts Information

Small clutch parts: Most of the small clutch parts are in this photo.

Top row, #17 840010 tab washer, #4 820502 hex bolt, #5 843500 washer, #6 480981 plate, #61 480892 leaf spring, #22 480887 saucer spring (used), #20 820520 splined bolt.

Bottom row, #24 813081 needle bearing, #23 816180 felt ring, #41 490814 washer, #22 480887 saucer spring, #79 480899 washer.

Saucer spring: You can see the shiny rings on the used saucer spring. They are where the contact was. The dark areas never touch anything. 

Leaf spring: The leaf spring goes on any one of the ten tabs of the friction plate, under the basket. What it does is reduce vibration. It stops the jingle bells sound, and helps the friction plate tabs last longer. It is not essential, but very beneficial. 

Crank Seals: Laura M48 uses crank seals that are 1 mm smaller (tighter) than normal.  The 15mm right side has a 14x30x7 seal. The 21mm needle bearing case on the left side has a 20x42x7 special seal with an offset lip. 

 

Friction Plate #480889: 10 tabs, each 10.5mm wide, inner diameter 58.5mm, outer diameter 92.4mm (100.4mm at tabs), thickness 3.65mm.

Note: The tabs break off when the slots in the basket become worn or notched on one side. This is because not all ten tabs are sharing the load evenly. A worn clutch housing/basket also makes the clutch stick and not go into “neutral”.  

 

 

Clutch Housing with Pulley #480880: 10 tabs, 10.3mm wide, ID 94.0mm, OD 98.6mm, center needle bearing ID 15.0mm, OD 21.0mm, length 22.0. Comes with the needle bearing only. Price $150 new, $100 almost new not worn. Far left, a new one and a worn out one. The slots for the tabs get worn wider where the plate tabs push at. Filing those flat will help, but it might still stick sometimes.

 

 

Clutch Housing Versions

480880 and 480894

480880 red has wide pulley for
US 25,30mph, Euro 40,45,50kmh
480894 yellow has thin pulley
US 20 mph, Euro 25,30 km/h

480880 clutch housing with pulley

480880 clutch housing
25.5 mm deep at crank

480894 clutch housing with thin pulley

480894 clutch housing
24.4 mm deep at crank

 

 

 

 

 

 

 

 

 

 

 

Clutch Washers: The Batavus crank goes from 12mm to 15mm right at the edge of the needle bearing. The clutch needle bearing is lubed by the gasoline and oil mist in the crankcase. The three special steel washers, one cupped, seal the crankcase pressure on the spinning crankshaft, along with the rubber crank seals.

 First the felt ring #23 goes into a recess in the housing-pulley #71. Then the large 15mm washer #41 goes on, just over the 12-15 step in the crankshaft. Then the 12mm saucer spring #22 goes on with the dish side up (outward). Then on 25 and 30 mph versions with the brick red pulley, the 12mm small washer #79 goes on, into the dish of the saucer spring. Then the aluminum clutch hub with large steel saucer in back goes onto the flat sided part of the crank, and rests against the #41. When the outer nut is tightened, the saucer spring is compressed slightly, so that the crankcase is sealed by the metal-to-metal contact ring between #79 and #22. When the engine is running, but the rear wheel is stopped, #79 spins, but #41 is stationary. Once the bike gets over 10mph, #41 and #79 are both spinning in sync, so the metal-to-metal pressure seal gets better.

 

Crankcase Pressure Leaks: All of this special washer business allows the needle bearing to never need greasing. But if a washer is missing, there is a small pressure leak. A small crankcase pressure leak causes a small loss of engine power at low speeds.

On a two-stroke crankcase the leak alternates in both directions. Piston going down causes some fuel mist to get pushed out. Piston going up causes some fresh air to get sucked in. Then the cycle repeats. Because of the rapid reversal of direction, at low engine speeds the leak has more time to happen, due to inertia. So the effect of leaving out one of the washers is to cause less “low-end torque”. The engine is weak until it gets going fast, then it is normal but lean.  

There is a small grease seal in the needle bearing #24. But it is not a pressure seal with a ring spring. So it is sealed partially, even without the washers. That is why leaving out the washers only causes a small loss of low speed power.

 

Engine Covers:

Motobecane magneto cover

1970’s Motobecane grey cover

Batavus clutch cover

1970’s Batavus black cover

Laura engine cover

1970’s Laura grey cover

 

 

 

 

 

 

 

 

 

 

Batavus M48 with late Motobecane magneto cover

1980’s Motobecane black cover

Angel

1970’s Angel grey cover

Laura M48 magneto (right) and clutch (left) covers are the same. There are different versions, including aftermarket, and different stickers.

Laura, Motobecane, Batavus, Badger, Angel, Speed Bird magneto covers all interchange, because they all have a 62 mm inner diameter. See Covers

 

 

 

 

 

 


3. Tools for Laura M48 Motor

1972 Anker Laura M48 tools116 crank bearing puller
117 crank bearing driver
118 flywheel holder
119 clutch holder/puller
120 flywheel puller
121 piston bushing press
122 timing gauge
123 clutch fitting sleeve
124 adapter M10
125 crank support plate
126 oil seal driver
127 oil seal driver