Leaking fuel cock

[Og-Whizzerdude]

I have two new edition Whizzers and four petcocks to shut the gas off from the tanks. Two and two replacements. All four leak. They dribble gas into the carbs when in the off position. I like to run the bikes out of gas for storage but the carbs eventually fill up with gas. I suspect there may be some parts in there that are not fuel proof. Any thoughts? I would like to find some with female metric threads that come out of the tank at a right angle to eliminate the "P" trap effect in the fuel line.
Thanks, Jim

 

[Quenton Guenther]

Hi Jim,

Which version of the fuel shut-off are you using? The later versions have a red plastic lever, whereas the earlier versions are all metal.

A recent upgrade was made by a friend in WI, and uses the vintage style float bowl filter with the shut-off built in. It looks like the vintage Tillotson version used on the Vintage Whizzer motors.

Have fun,

 

[Og-Whizzerdude]

They are all metal. I guess I would need an adapter for the metric threads if I went the vintage route. The way things are now the fuel lines slightly interfere with the choke levers. Not a big issue, they both run okay.
I do have a theory. It has been very hot in the Whizzer room outback. Averaging about 110° lately. I can hear the pressure release when I remove the gas cap. Could be the shut off just can't handle the pressure. Since I have extras I think I'll try to get one apart and see if I can find anything unusual.
Thanks for the info, Jim

 

[Quenton Guenther]

Hi Jim,

I have heard rumors that if the blue plastic piece were to fall out of the gas cap it might stop the tank from pressure and vacuum issues.
While running one of my Whizzers on the Roller Road the speed increased when the cap was loosened.

Have fun,

 

[Og-Whizzerdude]

I never did test my theory. I'll loosen one of the caps and see if it still dribbles. I seem to remember some gas cap issues on the oldest bike. That blue thing may have fallen out of that one. I need to check things out back there.
I know if the plumbing is not vented, the house won't drain but that's just methane, right.
Thanks Quenton. It's nice to get into these issues in the comfort of the A/C.
Jim