The wife's '99 has started spewing fuel out of one of the carb vent hoses.  If sitting on the bike, looking down to the left side, the vent hose coming up from the left side of the carb (throttle cable side) will spew fuel.  It does it mostly at idle.  From my older car carb experience, I suspected a dirty/damaged bowl float needle/valve assembly, allowing excess fuel to fill up the bowl and overflow out the vent, stopping at higher rpm due to more fuel being used, then overflowing again at idle.   I disassembled the carb and cleaned the needle and seat.  The needle seemed ok, couldn't visualize the seat valve real well (didnt remove it).  I pulled the top of the carb off, and there was obvious fuel in the area on top of the slide diaphragm, but the diaphragm looked intact and in good shape.  I cleaned it up and put it all back together, and it still does it.   Anyone have any ideas re; what else might cause this?  If not, I'll likely order up a new needle/seat assembly, but I want to rule out other possible causes first.  Thanks in advance.

Yonuh,
I did that... that's the float needle and seat that I cleaned and inspected.  

"I disassembled the carb and cleaned the needle and seat.  The needle seemed ok, couldn't visualize the seat valve real well (didnt remove it)."

If it is still leaking, then take it all apart and replace the float valve (needle) and seat, as said above.  There might be dirt in there.  Take the carb apart if need be.  Might need a new float valve too.  Don't just look at it.  That is the only reason that you have leaking out of the vent hose...

Of course, it starts at idle because the bike is running and the pete0ck is turned on because of the vacuum.

PS - I have a Vulcan in the garage that is spewing gas out of one of it's Keihins for the same darned reason.

Good luck.

Savage_Greg wrote on 12/31/69 at 16:00:10:

agreed - I sure don't see how it could get in there either except through the float needle - and sure doesn't take much of a wear ring to prevent it good seal - nor would it suprise me if this e-10 fuel didn't shorten the life of that little rubber tip

Oh yeah...what if the float don't float or is adjusted too high?

Yonuh Adisi FSO wrote on 12/31/69 at 16:00:10:

Migraines suck.  Not the same but similar pain...I just finished a cluster season.  Get your doctor to prescribe some oxygen.  Best medicine around.

Well, as I originally suspected, it was the float needle/valve seal.  When I pulled the old one to install the new one, I looked a bit closer, and there was a small wear ring on the needle.  The new one fixed the problem, with no further problems.  The wife was so stoked that it was working again.  We spent the whole afternoon putting around back roads, and practicing in a local community college parking lot.  She's scheduled to take her MSF course at the end of the month, and was dying to get in some "pre-lessons" and practice.  I logged on here to see if there were any other possibilities I should check before replacing the needle and valve.  Thanks to all who chimed in with ideas and suggestions.

newrider55 wrote on 12/31/69 at 16:00:10:


Ok, the first thing to check is the oil - is there too much and does it smell strong of gasoline? if so you have a total failure of the petc0ck diaphram - not real common - but it does happen and will toast your engine

2nd - is there even a little bit of fuel in the vac line that runs from the carb to the petc0ck - should never be any - if so you have a failing petc0ck diaphram - it will make it run rich and should be fixed before Item 1 can happen

Next up I think would be to figure out what has been done to the carb - like what jet's are in it now - some folks get carried away, and what if anything has been done to the white spacer.