Leaky petcock!!! 78xs11

[XS_CAFE_11]

Hi all - I am 120 miles from home - - #3 and 4 are leaking when I turn on the inline fuel valve - carbs 1 and 2 are working just fine - - - I think I know what the issue is but my question...can I run home on just one petcock????

[Crazcnuk]

I assume you mean #3&4 carb are overflowing when you turn the petcock on?

If so, it's not just your petcock that is leaking, it's also your float needles. (Or do you mean they leak even when the bike is not running?)

If the bike will run, you can drive it home, but it will likely be running very rich.

First, before you go anywhere, pull the fuel line off, at the petcock, that goes to carbs 3&4 and BLOW through it. This may clear one or both of the 'leaks' up.

You can also try to rap on the float bowls with a wrench or small hammer, to try and help the needles seat themselves.

Once you get the carbs working, we can deal with the petcocks, if needed.

[Ken Talbot]

And back to the most basic part of the question - no, you cannot run on just one petcock. Your early standard has two petcocks. Each one supplies a pair of carbs, and there is no interconnection for fuel between the left side and the right. A few of Craz's suggestions might help to temporarily minimize the problem. If it ends up sitting for a long time, still leaking, watch out in case the fuel also leaks through the carbs and floods into the crankcase, which will dilute the engine oil. You'll know if this has happened if the oil level goes way up beyond full.

[oldyam80sg]

Also you dont want gas dripping on hot engine parts-bad=fire

[DGXSER]

If you are close to a hardware store, and it is your petcock only, you could get a T and some fuel line (I used lawn mower stuff from Briggs and Stratton works great, no clamps needed.) You can connect one petcock to feed both fuel Ts. I have heard of others on the forum doing this with no issues of low fuel flow. It would at least get you home.

[dbeardslee]

A plugged vent will cause them to overflow too, and 3 & 4 share a vent line. If you've got pod filters with filters installed on the ends of the vent lines try pulling the one off that feeds 3 & 4 (some of them can get plugged easily). If you've got the stock airbox you can try pulling the vent off the box, but if nothing is right in the end of it I don't know how much good that would do. DO NOT blow compressed air down those lines (or any other lines, for that matter) with the float bowls attached - it'll crimp your floats. More details on your setup (intake, exhaust, mods, etc.) would be helpful in your signature. Could be the fuel valves, but you wouldn't expect them to go in pairs. Might try rapping on the bowls with the back of a large screwdriver in case the floats are stuck, but again, wouldn't expect it in pairs. Worth a try though.

[wa407mpp]

Has this been a problem before? like when the tank is full and it is a hot day. those two events coupled with a weak spring or a bad gasket in the valve can cause it to not shut off when parked. If the problem with in the gasket in the petcock you can some times do a temporary fix by moving the lever back and forth a few times then tap the face of the valve, the part that pivots, a couple of times, that may seal it until it is moved again. If it is a weak spring in the valve in the petcock and you have to ride it to get home you will probably have to follow drexer's advice and t it off.