C. Filters, Fittings, Hoses, Seal Rings

 

Inline Fuel Filters

3/16" inline filter round clear

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C1
3/16″ inline filter, round screen type, 12-1585 $5

 

1/4" inline filter round clear paper

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C2
1/4″ inline filter, round screen type, 15-1520 $6

 

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C3
1/4″ inline filter, 90 deg paper type, 15-1796 $3

 

Screw-on Adaptors

C4: 10×1 male to 12×1 male adapter  N/A

10x1 to 12x1 gas valve adapter

C4 adapter
a) separate (yellow box)
b) assembled with valve
c) installed in 10×1 tank

McMaster-Carr 50915K317 brass compression tube fitting

McMaster-Carr 50915K317 fitting, end cap discarded,
1/8 npt-17 to 1/2-24
can be rethreaded
to 10×1 and 12×1

Sometimes a gas tank has a 10 x 1 threaded gas valve hole that is close to a “wall”, preventing the gas valve from screwing on or off, unless the tank is removed. Sometimes removal of the tank is very difficult, like on a Cimatti City Bike. In those cases an adaptor fitting can be used to convert to a turn-buckle type gas valve, where only the nut turns. 

A 5/16″ OD hydraulic tube fitting has a 1/2-24 thread, that can be cut down (rethreaded) to 12 x 1.  The end cap is not used. Then it becomes a moped gas valve adapter. A tight-fitting 10mm washer made of plastic, paper, or other semi-hard material provides the seal, not the threads. The 12×1 die is not in most metric die sets.

 

 

Screw-on Extenders

What is an extender and when is it needed? An extender is a piece that moves a M10-1.0 screw-on valve away from the tank.

1. For when the petcock handle hits the tank in the up (reserve) position. Most original valves had reserve pointing up, ↑reserve  off→ on↓. Original valves with an up position often had to be moved away from the bottom of the tank with an extender, to allow the handle to go straight up and not hit the tank. Some tanks had a welded-on extender, a short pipe with a 10×1 threaded hole. Some original valves had screw-on extenders. 

For this reason, most modern replacement petcocks do not have an up position. They have ←reserve  on↓ off→. That eliminates the need for an extender, a cost saving improvement.

2. For when the petcock passes through a hole in a body panel. The correct extender length lowers the petcock to the level needed to pass through a hole in a cover panel. So the petcock is hidden except for the handle, for a clean look.

3. For when something prevents installation. Sometimes part of the gas tank or frame prevents the screw-in petcock from screwing in. An example is Peugeot 102.

..part#  price  extension
C10.11   $13  11.0 mm = 10.0 mm extender + 1 mm seal washer
C

C10.12   $14  12.0 mm = 10.0 mm extender + 2 mm seal ring
C

C10.145 $13  14.5 mm = 13.5 mm extender + 1 mm seal washer
C

C10.155 $14  15.5 mm = 13.5 mm extender + 2 mm seal ring
C

C10.195 $14  19.5 mm = 13.5 mm extender + 6 mm cup seal
C10.195 $00  1980 Peugeot 102 SP (required)

C10.22   $26  22.0 mm = 10+10 extenders + 1+1 seal washers
C

C10.23   $27  23.0 mm = 10+10 extenders + 1+2 seal washers
C

C10.25   $13  25.0 mm = 24.0 extender + 1 mm seal washer
C

C10.26   $14  26.0 mm = 24.0 extender + 2 mm seal ring
C

C10.30   $14  30.0 mm = 24.0 extender + 6 mm cup seal
C

 

 

 

 

 

 

 

Seal Rings

C13 seal ring    10-14 x 6  w/metal cup 10.4-16-4.5  $2
continued soft, for light tightening, seals over a wide range

C14 seal 0-ring 10-15-2.5 w/metal cup 10.4-15-3.5  $2
continued soft, for light tightening, seals over a wide range

C15 seal ring   10.0 id, 13.7 od, 1.8-2.3 tall nylon $2.00
continued hard, can hold up to tightening pressure

C16 seal ring     7.5 id, 10.5 od, 1.7-2.1 tall nylon $2.00
continued hard, can hold up to tightening pressure

C17 seal ring     7.9 id, 10.4 od, 1.4-1.8 tall fiber  $2.00
continued hard, can hold up to tightening pressure

C18 seal ring     8.0 id, 11.7 od, 0.0-1.0 tall fiber  $2.00
continued hard, can hold up to tightening pressure

Many more of these are listed in Parts/Engine/Seals and O-Rings

 

Turnbuckle type nuts (forward and reverse thread)

These special nuts have “forward” right-hand thread on one side and “reverse” left-hand thread on the other side. The left thread side screws onto the valve, and the right thread side screws into the tank. This allows a screw-on valve to be tightened without the valve turning, and allows the valve to face any direction 360 degrees after tightening.

C20: 22 x 1 internal right to 22 x 1 internal left  turnbuckle nut   $7 chrome

C21: 16 x 1 internal right to 16 x 1 internal left  turnbuckle nut   $2

This turnbuckle type (LH and RH) nut is used on all 16mm female (internal-thread) moped gas valves.

C21a: 14 x 1 internal right to 14 x 1 internal left  turnbuckle nut   ??

C22: 12 x 1 internal right to 12 x 1 internal left  turnbuckle nut   $1

This turnbuckle type (LH and RH) nut is used on all 12mm female (internal-thread) moped gas valves. 

 

C23: 22 x 1 internal right to 16 x 1 internal left  turnbuckle nut   N/A

This new nut was made improperly. The 16 x 1 left thread ID is to big (so it would strip off the soft alloy threads of the petcock when fully tightened) and the center-line is not straight (so the sealing surface of the petcock is at an angle to the sealing surface of the tank).

C24: 16 x 1 internal right to 12 x 1 internal left  turnbuckle nut   N/A

There are two things to watch out for with these dual diameter dual thread nuts.

1. There are two ring-shape sealing surfaces on the petcock that must be close to the same height when the nut is fully tightened. The outer 

2. The ring-shape sealing surface on the gas tank must be wide enough to press against both of the petcock sealing surfaces.

 

Hoses and Parts

C29 clear nylon hose 3/16″ id 5/16″ od $1/foot fits moped spigots 5mm, no clamps

C30 soft aluminum tubing 1/8″ od $0.50/inch for making reserve tubes, longer or curved upward
continued easily bent, often must be ground slightly for press fit into hole

C31 “Y” connector for 3/16″  hose $3 for joining two fuel lines into one upward
continued for making a clear hose external fuel gauge, or for dual gas tanks