Leaking Gas

[sammer77]

I have a 1981 GS650L that is leaking gas out of the airbox hose while sitting. The valve on the tank is Reserve, On, and Prime. It remains in the on position. This just started in the last week. Any ideas on what causes this? The carbs are not leaking out of the float overflows.

Thanks,
Mike

[Billyboy]

How much gas? Lots? Or just a drip. Either way, shouldn't happen.

Are you sure that its the airbox hose? There's a tank breather somewhere near the gas guage sending unit.

[sammer77]

Yes, it definitely coming out of the hose from the air breather. Just dripping every so often. Smells bad enough that I can't keep it in the garage.

[fwwrcpg]

I thought i was having the same problem. When I checked it was actually coming from a small pin hole in the gas tank. The gas was actually leaking on top of the air box and make it look like it was coming from the air box.
Went down and got some gas tank putty and not a drip.
Hope this helps

[argonsagas]

First, let's be sure you do not have the petcock set to PRI, which allows the fuel to flow directly from the tank to the carbs. The other settings permit fuel flow only when there is engine vacuum.

Normally the fuel line runs from the tank to the rail that distributes the gas to all the carbs and stops there.

Presuming you have made no modifications to the fuel system gas can only reach the airbox after it first goes through the carbs.

That means one or more of your float valves is not sealing correctly, and, if the petcock is positioned anywhere other than PRI, it is also not functioning correctly.


Now that you know fuel is leaking, be sure to check your crankcase, as you may find fuel mixed with the oil.....not a good thing. A tiny bit does not matter, as it will evaporate, but anything more thins the oil and can cause lubrication problems. A lot more and you fill the crankcase and that can lock up the engine.