Velocette-Efforts to keep the oil inside

If you have been around Velocette motorycles, you may have noticed that they tend to mark their locations with a puddle or a trail of oil.  Veloce made little efforts to contain the oil needed to run these fabulous machines, as becomes evident once one takes one apart.  Over the years, owners have come up with some ingenious was to add seals and find ways to lessen or slow these leaks.

The idea of this post is to start to document some of these ideas and share them with other Velocette owners.

KICKSTART SEAL

This is a fairly simple one and is available from Groves directly.  I used the SKF 7415 seal.

TACHOMETER (REV COUNTER) SEAL

This one is done using a 3/8" valve guide seal and a simple part made on the lathe.  I used a Kibblewhite 37021 3/8" x 0.562" valve guide seal, but any 3/8" valve guide seal could be used and the adapter made accordingly.  The adapter is installed using a bit of gray RTV.

PRIMARY CASE CLUTCH SEAL

The later bikes used a felt seal (if you can call it a seal) between the outer chain case and the clutch pressure plate.  There is a modern seal that does a better job in this location.  This is a seal numbered 400950 (SKF also makes it as well). The seal is installed using some black RTV.

CYLINDER STUD TO HEAD SEAL

The following was done on a Thruxton, as it came to me with standard O-rings that were intended to seal against the stud threads.  Since the threads leave a path for the oil, I figured that I would seal them up with some high-temperature silicon and then use silicon O-rings (higher temperature rating).  I do not have confirmation from the owner of this machine to know if this worked.

The threads are glass bead blasted and then cleaned with a proper solvent.

The masking tape limits where the sealant is installed, and helps set a level for it. 

The sealant is leveled across the masking tape surfaces using a putty knife.

Silicon O-rings are used.  The smaller cross section version was used.

The sealant ends at the top of the O-ring.

GEARBOX SLEEVE GEAR TO MAIN SHAFT SEAL

This is a suggestions from Jim Romain.  In my case, I sent him my sleeve gear and main shaft and he installed a new bushing and seal.  The seal is an SKF 8009 (20.65mmx27mmx3.16mm).  The groove is cut on a lathe using a CBN (cubic boron nitrite) cutter, since it cuts into the hardened sleeve gear and not just the bushing.  I am trying to locate some photos of this modification and will add them when I have them.

Note: The intention of these articles is to share my experience for the use of others working on Velocettes.  For this reason, please feel free to share comments, edits and suggestions to make this more accurate or clear.

Blaise