03 Warrior Trouble

[calhouncm]

My friend bought a 2003 Yamaha Warrior 350 not running. The last owner was having carb troubles. He put a new needle and seat in it to try and cure the problem but it didn't do the job. I pulled the cover off the air cleaner box and it was half full of gas. I took that off and dumped the gas, without the air box on I turned it over and it started right up. I assumed either there was something between the needle and seat not allowing it to seat correctly or the float height was set incorrectly.

I pulled the carb, cleaned up where the fuel comes into the carb and against the seat. After that I put the carb back together and put a clear plastic hose on the drain pipe and loosened the screw on the bottom of the fuel bowl to see how high the fuel would go. From what I have read the fuel should be as high as the fuel bowl surface. After a couple of adjustments I had the fuel so it would stop at that height. When I put the carb back on and got everything back together it ran fine again for a few minutes and then would not idle and died out. At this point I saw fuel coming out of what I believe to be a breather on the top of the carb. There is a black hose connected to the pipe which had the fuel coming out of it.

What would cause fuel to be able to make it up this high in the carb? I checked the airbox again at this time and there was no fuel in it.

[jcole1325]

Check your pilot air jet. Weird. Air pressure must be pushing the fuel up to the breather outlets. But why? To rich maybe. Sorry not to be a lot of help but you got me curious. Let me think about it.

[yimcyco]

your sympton points to a float valve problem check to for excessive play with pin and pin holder

if okay moose make a rebiuild kit for it

you also may be experiencingspin back though the intake so check your valve clearance

with that much fuel in air box i would change my oil due to fuel contamination

spark plugs may also be foul due to excess fuel