Gas tank petcock

[Rex]

I have a reproduction gas tank petcock that consists of a brass body and tapered rotor. There is no packing or o-rings, and of course it leaks fuel past the handle end. I don't know for sure yet, but I assume it's also leaking through to the fuel line.
The Palmer book suggests lapping this valve, which I have tried without success. I'm trying to keep this project "period correct", and don't want to use hose and clamps. Any ideas?

[roland]

petcock

Hi Rex.
I am assuming you lapped it in correctly with rough and then fine lapping paste? if the rotor is badly scored then you will never get it to seal by lapping, but you could try filling in the scoring with devcon epoxy metal filler. Also try some of your local plumbing stores, some of the 1/4 and 3/8 valves used on gas lines are of the same type used for petcocks and you may be able to adapt the rotor to fit your petcock valve, I have done this myself and had great success with them. It is worth a try any way.
Cheers for now Roland.

[Rex]

gas tank petcock

Roland,
Thanks for the reply. Yes, I've progressed through the series of lapping compounds and am now beginning to see some results.
I don't have the scoring problem, but using blue machinist's layout dye it looks like the rotor and the body are contacting only at the points where the rotor enters and exits the body.
I don't have much confidence that this valve will work long term, and am persuing alternatives. Jerry Greer has a valve that looks promising. I found a brass bushing that will adapt the 3/8" pipe thread in the tank to the 1/8" pipe thread on the inlet side of this valve. The valve outlet threads are correct for my fuel line.
Rex

[roland]

petcock

Hi Rex.
I have a few gas petcocks in my garage, what make of bike is your's from and about what year. I may have one that would work for you, if I do your welcome to it.
Cheers Roland.

[Rex]

Gas Petcock

Roland-
I'm building a 1937 HD 45, so I have a 3/8" pipe thread in the tank. Yesterday I found a bushing at NAPA that will adapt one of Jerry Greer's Indian petcocks with a 1/8" inlet to my tank. The outlet thread is correct for my steel gas line. I ordered it today before I saw your generous offer.
I'll let you know how it works.
Rex