Stock 400 carb leaking?

[T.Hopp]

I noticed today that gas was constantly draining out of the float bowl vent line. As a test I plugged the vent. Sure enough it then leaked out of the other vent line. Pulled it apart and inspected the float. It moved freely. I check a general service manual and it showed that the float valve could develope wear marks at its closed positon that could allow fuel to enter. I check for this but it has no signs of it. Anyone have any other ideas? Note: Bike ran fine except for leaving a trail of gas.

[LazeR]

Did you pressure wash your quad ? I pressure washed mine started it up and it was draining gas outa the overflow line! I at first thought it was because i didn't have the clamp on the line that went to my gas tank from the carb, and maybe it was getting air! well i put a clamp on it and same thing! Finally before tearing it apart i drained it totally outa gas well i just turned off the gas and let it run until it died, waited a couple mins (i had it warmed up) started it up, let it run for a second and rev'd it up a lil bit! and now it doesn't do it anymore

[T.Hopp]

First I will mention that the quad isn't mine. Now I will say that it ocasionally sees fresh water from a hose. Nothing more. It has me stumped at the moment.

[JOEX]

What quad and what year?

I have heard rumors that the earlier 400ex's had issues with the float sticking. I think that is what is was;)

I don't know what correction is needed to rectify the situation:(

[T.Hopp]

It is on a 2000 400EX. Another thing, I set the gas tank on the edge of a workbench, attached the carb and let it hang from the tank. When I shook the carb, it would load up the bowl and drain out the overflow tube. Once it drained so far it did stop. I inspected and cleaned the float and bowl thuroughly of any debris. Although it looks fine ,I suspect the float valve not seating properly. Gas still flows into the bowl while the float is up. My unprofesional thoughts.

[cals400ex]

yep, the carbs were "revised" in 2001. i think it was just the float pin or something like that. my friends would leak gas out of that hose when climbing hills or doing wheelies. it would also stumble and miss on really steep hills. he had the dealer replace the part with the the updated version and the problem was gone. i will try to find a thread on it.

[T.Hopp]

That thread would be great! Thanks.

[cals400ex]

this may help:

http://www.exriders.com/vbb/showthread.php?threadid=36570