Gas leaking from breather pipe

[YellowJacket!]

Well, yet another V Gremlin has awoke in my bike.  Today I noticed a pool of gas below my bile while it was idling.  Funny thing is that the idle would be stable at about 1500 then shoot up to 4500, stay there for a bit then drop down again.  The fuel would leak while the RPMs were high.  I traced the leak back to the "breather pipe" or the small plastic fittings - 2 part on front carb and single on rear - on the bottom of each carb bowl. The hose goed back to the space where my relays are and drains into a hole in the pan above the exhaust collector.  Apparently there is a small hole and the fuel then drains onto the center stand and -great balls o'fire - onto the collector.  Just a great way to send me and my V into a burning inferno!
So, from all the wonderful collective knowlege here, what causes it and how do I fix it?

Thanks,

David

[h2olawyer]

David -

The fuel is coming out the overflows.  It sounds like you have a sticking float.  Some gentle tapping on the float bowl may loosen it back up.  Your float could be slightly mis-adjusted (too high) as well.  Something is preventing the needle from sealing properly in the seat.  Is your petcock set on "PRI" or "RUN"?

The RPM thing has me a little perplexed - it could be a vacuum leak in the fuel pump system - either in the vacuum line or within the pump itself.

The fuel overflow tube should be long enough to dump the fuel on the ground.  The tube should pass through the hole in the frame behind the engine (over the center stand) and drip in front of the exhaust collector.

There may be other ideas floating around out there, but these seem to be the most common & likely culprits for overflow leaks.

Hope this helps.

H2O

[YellowJacket!]

The petcock is in the run position.
My guess is the hunting idle may be related to my YICS, so Im going to disconnect it.  I leak tested it and it is solid, but its about the only variable right now.

David

[Superfly]

I just had something similar (minus the rpm's) happen and I swapped out the valve needle & seat to fix the problem. ?If you take off the tube that connects the 2 plastic drains, you will be able to see which carb the fuel is flowing out of.

It sounds like something else is wrong also, if your RPM's are shooting up, that could be a sign that you have a vacuum leak somewhere, or you need to clean your carbs again (I am sure you have done it already) but sometimes theese things need a couple of rounds! ?I have dipped carbs multiple times to get them completely clean. ?Hence, the quote at the bottom of my post!!

[Lucky]

Hey Superfly, i'm going to put dirty carbs on my vacuume cleaner & see if it sucks better, lol :D

for the rpm shooting up like that, yeas, double check the YICS, but also look for a split hose, those YICS hoses take a beating.

if it's a stuck float or leaky needle then it makes sense that it ony overflows when the rpms are high at idle, the fuel pump is pumping like crazy.

--Lucky

[YellowJacket!]

YICS Hoses are brand new.  I used high pressure braided fuel injector lines.  Stiff and tight.  I did your test(lucky) by blowing into each port on the YICS and there are no leaks at all...except in my eardrums now.     ;)

David

[MotorPlow]

I had this same thing happen to me (w/o the high idle):
http://motorplow.blogspot.com/2005/04/thank-you-mr-murphy.html

It was a simple fix for me.

[YellowJacket!]

Hey chris, thanks for the link to your site.

I'll try your fix this weekend.
Thanks everyone for the help.

David