GS range with Diaphragm petcock

[feelergaugephil]

If the gas is turned to main and not res or prime, if the diaphragm is wore out will it leak into the carbs??
I just got my tank back, fired it up, runs great, but next day my garage smelled badly of gas and looked like #1 air filter area was dripping gas all night, any ideas guys?
I just took it to the local tune up garage that sets up the carbs on bikes, so it should be back in a day or 2, as it ran good but a bit rich.

[Anonymous]

Re: GS range with Diaphragm petcock

[quote="feelergaugephil"]If the gas is turned to main and not res or prime, if the diaphragm is wore out will it leak into the carbs??

Yes, and into the crankcase, too. There are rebuild kits out there.

[KEITH KRAUSE]

If the diaphragm is worn, it will leak into the carbs.
To test, install a piece of clear tubing folded back on itself, or run a tube to a jar and let the bike sit overnight as you would normally. Any fuel is a leak.
If it didn't leak, then the fuel that's left in the fuel line and carb passages to the bowls is enough to drain past a poor sealing float valve and flood that carb. You can also check for a leaking float valve by installing a clear fuel line. After turning the bike off, note that the fuel line is full, or maybe has a small bubble in it. If the fuel level drops noticably by morning, you have a leaking float valve.
If the leaking is a valve, you may be lucky and just need to clean up the valve and its seat. Check for any burrs on the sides too. If a ring is worn deep enough around the valves tip (metal or rubber tipped), it's bad. If the valves spring is weak and its full travel is not under spring tension, replace the valve. If you can pull out the little pin more than the spring pushes the pin, the spring is weak.
Sometimes the float seat gasket or o-ring is leaking and allowing the bowl to overfill. It can also be a high float height or sticking or punctured float. Most often the leaking is the valve though.

[feelergaugephil]

Carbs

Well, Keith! Your right again!
Petcock is leaking slowly then when it gets down to the carbs, the float needle is sticking up, hence fuel getting into pistons hence crancases FULL!
So I just ordered new petcock replacement stuff and 4 new needles and seats. so yet again, another few days waiting for snail mail. Thanks again Keith.
Ps! I wont forget to drain out the new oil too!

[KEITH KRAUSE]

Be sure to measure the float heights after installing the new float valves. Since the carbs will be off, if it's been awhile since the manifold o-rings were replaced, I'd replace them too. Good luck!