Long story short:
I replaced the gas tank on my wife's GS500E after having her original one painted and damaged upon reinstalling.
The tank I purchased had to be resealed with Redcoat tank sealer, and apparently it's sealing just fine given the pressure that's building up in the tank!
Problem?
I think it's the gas cap combined with this tank. The cap year is unknown because the tank that was on the bike when we bought it was not original. I do know that the new tank is definately a 1992 year model, and for what ever reason the cap was not a 100% bolt-on affair. i had to remove one of the fake allen heads and trim the shaft of it off to clear a dowel that was molded in the tank where the cap bolts in to make it fit.
My real question here:
Is there any way to create a vent? I don't mind if there's a potential for a bit of fuel seepage if the tank is 100% full, because it;s my wife's bike that will never be wheelied or stoppied, and I can just not top the tank off ever.
I just need this thing to vent because I believe it's causing the carbs to leak when sitting overnight. I've been popping the cap open at random to relieve the pressure built up, but I'd like to rest assured that fuel's not going to be leaking on my wife's engine casings while she rides for extended periods in the summer heat.
Thanks in advance for any help.
Quote from: B18C5-EH2 on June 19, 2006, 01:53:35 PM
The cap year is unknown because the tank that was on the bike when we bought it was not original.
But, is it a GS cap? I vaguely remember someone stating that a GSXR cap will fit, but it doesn't vent as well (hence the tube that comes out of the top front of the GSXR tank, like an old dirtbike cap vent tube).
Quote from: B18C5-EH2 on June 19, 2006, 01:53:35 PM
I've been popping the cap open at random to relieve the pressure built up, but I'd like to rest assured that fuel's not going to be leaking on my wife's engine casings while she rides for extended periods in the summer heat.
Usually, the float level set too high will result in fuel overflow from the carbs. Is it overflowing from the airbox drain tube? Or, is it in your oil and your oil smells like gas.
did you re seal it with the cap on the tank?
if yes, you just need to take the cap apart and clean out the vent line in the cap
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But, is it a GS cap? I vaguely remember someone stating that a GSXR cap will fit, but it doesn't vent as well (hence the tube that comes out of the top front of the GSXR tank, like an old dirtbike cap vent tube).
It has to be a GS500 cap because it worked flawlessly with the tank that came on the bike when we purchased the bike.
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Usually, the float level set too high will result in fuel overflow from the carbs. Is it overflowing from the airbox drain tube? Or, is it in your oil and your oil smells like gas.
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No fuel in gas at all. I just checked the oil yesterday. The gas I'm getting is collecting on the big flat area just behind the cylinders on the lower cases. It is dripping from the idle adjuster on the carbs from what I can tell. since popping the cap at random the fuel has all but stopped leaking from there.
Quote from: werase643 on June 19, 2006, 04:19:19 PM
did you re seal it with the cap on the tank?
if yes, you just need to take the cap apart and clean out the vent line in the cap
No the cap was not on the tank, and nor was the petcock, or any accessories at all.
I've already made sure the overflow drain was clear, and it is. I also removed the cap yesterday and sprayed compressed air and carb cleaner through the vent on the cap. It seems to have really helped, but I'm not 100% sure it's a complete fix yet.
Are there two distinct types of GS500E caps from 89-01? It's just too weird that this cap fit fine on the first tank, but needed to be modified to fit right on this second tank.
Is the drain hose under the tank in place? It goes from the nipple on the underside to the bundle of hoses that ends by your right foot. If not, any overflow from the cap region will spill in the region of your carbs and may then be dripping where you describe.
Quote from: MarkusN on June 20, 2006, 06:24:00 AM
Is the drain hose under the tank in place? It goes from the nipple on the underside to the bundle of hoses that ends by your right foot. If not, any overflow from the cap region will spill in the region of your carbs and may then be dripping where you describe.
It's definately in place, and I already blew through the tube and the air flows free through the top of the tank, so there's no blockage at all.
I know it's a pressure issue because her bike never did this before, and my 00 SV650 never builds pressure to where it hisses when I release the cap door.
I just wanted to verify your observations re: the different styles of caps. I had to drill out the lock on my '00 tank and I bought a used cap assembly to replace it. I found the same thing you did - that little post on the tank interferes with the stud on the back of the cap ring. Rather than grinding it down I just rotated the cap 180 degrees and mounted it that way.
-M
Quote from: B18C5-EH2 on June 20, 2006, 06:19:53 AM
It is dripping from the idle adjuster on the carbs from what I can tell.
We need to know exactly where this leak is originating.
Quote from: B18C5-EH2 on June 20, 2006, 06:19:53 AM
since popping the cap at random the fuel has all but stopped leaking from there.
So it's still leaking, which means that it could be a leak independant of the pressure; the pressure just exaggerates it; is the bike being left in the sun?
The bike is garage kept, and even the garage door has no windows for the sun to beat through to heat the bike up.
Also I've tried to pinpoint the leak, but thus far have not been successful in doing so.
All I can say is the gas was dripping from the idle set screw with the spring on it, which to me seems like the carb itself was leaking because of pressure built up in the tank.
The tank itself could not be leaking, because gas would leak out of the tank far sooner than vapors would, so if the tank pressurizes then the tank itself can't have a hole large enough for gas to leak out, right?
Also let me repeat that the carbs did not leak a drop of gas before the tank was replaced.