Fuel Leak, HELP!!!

[adamwade]

I'll try to keep this short.  I purchased a '91 GS about 3 weeks ago.  When I got it home, I noticed a small fuel leak that was dripping from the bottom of the carbs.  I pulled everything out, but could not find the source.  So, I found a clean one on eBay and installed it.  Same problem!!  So, i took the newer one off, went and bought some newer hose clamps to attach the carb to the block, hoping this was the problem.  No luck.  I've checked the tank, the petcock and all the lines and they are dry as a bone.  The bulk of the leak seams to be coming down between the carbs and collecting on the idle screw.  Any ideas?

[Kerry]

The drip isn't coming right from one of the the float bowl drains, is it?

What if you feel around the area where the fuel hose from the ON/RES/PRI switch meets the lower T-connector between the carbs (item 64 in this diagram)?

If that's dry, then run your finger around the float bowl gaskets (item 27 in the diagram) on both carbs.    Perhaps you need to replace them?

=======

Meanwhile, does the bike start and run?  I'm only asking to make sure that the carbs aren't overflowing with fuel because of a stuck float valve and a fuel switch set to PRI.

[adamwade]

The leak happened on both sets of carbs.  That is what is making me think it is not in the carburetor, but maybe something else.  The bike runs fine.  The leak only occurs when the bike sits and is off.  The carbs have been jetted, and there is also a K&N oval air filter.

[Kerry]

The leak happened on both sets of carbs.  That is what is making me think it is not in the carburetor

OK, that would make my 1st and 3rd suggestions unlikely.  But BOTH sets of carbs would be connected to the fuel selector switch via the supply hose.  Perhaps the hose is cracked or expanded near that T-connector and/or the little clamp isn't sufficiently tight?

Speaking of the fuel selector switch, you didn't mention which position you leave it in.  It wouldn't NEED to be in PRI to leak -- I'm just curious.

The leak only occurs when the bike sits and is off.

How can you tell that it doesn't leak while you're moving down the road?  If it's a slow leak, maybe the dripping fuel evaporates away in the turbulent air...?

[adamwade]

When I fire the bike up and let it run in my garage, there is no leak (that I can tell).  My first thought was that the throttle needle wasn't setting properly when off, and allowing fuel to keep running into the carbs.  But, for the problem to happen with both sets of carbs, I ruled that out.  I leave the fuel selector on "ON".  That's what was leading me to think it was something in the intake flange.  The old "clamps were a little worn, so I replaced them.

[scratch]

Try this as a test: When you let the bike sit for a while, drain the floatbowls of the carburetors. If you still have gas leaking, it will not have been from the floatbowls or the 'T' fitting. You will have eliminated that part of the bike as being suspect.