hello. im a new user to this site and am wondering if anyone has encountered a similar problem to the one i am having. i own an '04 gs500f with approx 17000 km (10500 miles) on it. my problem is that it will leak fuel out of the airbox drain tube. its leaks with the bike off and fuel petcock in ON position. it has done this 3 times now. the first time it happened was right after washing my bike (was not ridden prior to washing) i cleaned the carbs and reinstalled, took for a ride, left it on my driveway for about 20 minutes and came back out to find a puddle of gas under my bike. after that i cleaned the carbs again and installed an in line fuel filter before the 'T' fitting to the carbs and, until recently, it hasnt done it again. yesterday i was washing my bike and noticed it was leaking gas again! i seem to have this problem everytime i wash my bike (something is getting wet / cold and causing this problem) i didnt spray with water while it was hot (it was sitting overnight before washing) can anyone help me out?

maintennace on my bike so far :: carbs were balanced at suzuki dealership 3 times, right cylinder exhaust valve was replaced (appeared to be bad casting), a few oil changes, added inline fuel filter, carbs have been cleaned.

Sounds like you covered all the bases.  Since it only happins when you wash your bike, how about this suggestion (kind of crazy, I know)

Are you sure it's the airbox drain tube and not the tank vent hose.  They run right next to each other out the bottom of the bike...well at least they do on the E.  If you got some water past the gas cap it would drain out of the tank vent hose, rinsing any gas with it.  Is it alot of fuel?  

I know, kind of "out of the box" but figured I'd throw it out there. 

No water other than rain has ever been sprayed on any of my bikes.. They get cleaned w/ spray polish  The first time takes a while but after that if you keep after it its easy. Now I can clean my whole bike in less than 10 mins and you dont have to dry it off 

Quote from: scottpA_GS on August 19, 2009, 11:32:39 AM

No water other than rain has ever been sprayed on any of my bikes.. They get cleaned w/ spray polish  

No spray polish has ever been sprayed on my GS.  It would be a waste of spray polish.  

Could it be a problem with your fuel petcock?  You might check to see if it is passing fuel with the engine off. I'm pretty sure it's a vacuum operated petcock while in the on position and should only let fuel flow with engine running.
Tony

If any fuel gets to the air box then it gets there past fuel floats ,so first check float height 

I'm thinking it's water and not gas.  If your floats were sticking open your bike would run like crap.  If you don't have the petcock on PRI, (prime) gas leaking out the air box is very unlikely.  It's the vacuum operated petcock's job to keep that from happening unless you defeat its purpose by leaving it on PRI.

hey thanks for the posts i can use all the ideas i can get  . it is definately not water and it is not a drip. it is a constant stream of fuel coming out of the airbox drain hose (until supply is shut off under tank). it could be worn floats but is this common with only 10 000 miles on a bike? plus it does this when petcock is in "ON" position. i know this is a vaccuum operated system and fuel should not pass the petcock when it is in ON position. is there any way to test the petcock?