petcock question

[wharrah]

Ok.

I started a thread (that I can't find right now) yesterday, where i found my GS with a gas puddle underneath, and it wouldn't turn over. Today I changed the oil and filter, still wouldn't turn over. Then I pulled the plugs, and (just as I suspected) had one that was full of gas. IT was number 3.

Cranked it over, caught the fuel, put things back together and it runs perfect.

But... I thought my leaking fuel was the result of the petcock being slightly towards the "prime" position, rather than 90 degrees from either "prime" or "reserve". I guess that isn't so.

I still have my gas leak, draining out of a vent tube near the center stand.

Do I try to fix the petcock I have (that is obviously now leaking) or do I try something else? Like a dummy, I put two gallons of gas back in the tank after I got it all "fixed"... so now I have a bunch of gas to lose. its a really slow drip, but it still happening.

I had started to notice my MPG had dropped from over 40 to about 35 the last time I fueled up, which had stumped me til I found my cause.

Thoughts?

I'll probably go for a drive tomorrow and burn some of the gas off rather than lose it. But, this is a bummer. Its fixable, but still a bummer.

[KEITH KRAUSE]

I'd get a piece of line and drain the fuel into a gas can. You're going to have to drain the tank anyway to repair the petcock. You should be able to get a rebuild kit that includes a diaphragm?

[wharrah]

A reasonable idea. I'll have to try and find some parts I guess. Does anyone know if they make manual petcocks? Would one of them be better than trying to fix a diaphram-type original one?

[dogeatshouse]

A reasonable idea. I'll have to try and find some parts I guess. Does anyone know if they make manual petcocks? Would one of them be better than trying to fix a diaphram-type original one?

I just had the same issue with my 1980 GS750E. I could see the gas leaking from the petcock gasket so I replaced it with a pingel petcock. More expensive than a stock rebuild, but very nice. That was only part of the problem though. Once I replaced petcock, I too had fuel gushing out of airbox and from overflow tube under the bike. Going to have to rebuild carb, float valve sticks open, thus all the extra gas when I try to rev it past 4000 rpm. You'll probably need to change your oil and filter again too if this is what's going on for you.

[KEITH KRAUSE]

A reasonable idea. I'll have to try and find some parts I guess. Does anyone know if they make manual petcocks? Would one of them be better than trying to fix a diaphram-type original one?

I bought a Pingel valve. Mine was $90 including adapter plate. No more worries. If interested, you may want to call them just to see if there's any problem fitting one in your tank.
Mine ('79 GS1000E) mounted fine. Just had to enlarge the hole a little with a file so the valve would go into the tank. Very easy.
Some owners say they've had to shorten the tower of the Pingel a little to fit certain tanks. That's supposed to be easy too.