Lately when i get on the gas on my 400 it falls on it's face about half way through the rpm range. It seems to be worse when I am turning to the left. It won't even power slide any more. When I go straight, it does this some, but not nearly as bad. I'm baffled. I put in new gas, gas line cleaner, nothing has fixed it. Any help would be appreciated. I'm not a mechanic but can do some work on it.

 

Did you check out the carb? partially clogged jet could do this as could a sticky needle valve.

I had mine do something similiar I took the bowm off removed the needle valve and blased the seat in carb cleaner. I then squirted the crap out of the needle valve and put it back together and my problem stopped.

I tried fuel treatment before I cleaned the carb out and the problem didn;t go away.

 

I took the carb apart, but didn't use any cleaner. (I'm busy with harvest right now and don't have any cleaner around) I'll try that. I also have not blown the main jet out. To do that do I just take it off and use compressed air or what. (I'm a farmer not a mechanic and this is just a fun toy[img]i/expressions/face-icon-small-smile.gif[/img]) What do you recommend for cleaning the carb and needle?

 

I think I fixed it. I found a line coming off of the top of the carb that had gotten over against my pipe and eventually got melted off the almost sealed from the plastic melting together. So I got a pair of scissors and cut the melted end off. Runs great now. So if my cutting this plastic hose off shorter is going to do damage to my engine, someone let me know...otherwise, we'll see ya on the trails.

 

ha ha ha ha ha.

I had the same thing happen to me once only mine melted shut against the pipe. bike would run for two minutes then die, I would let it sit for ten and then it would run another ten minutes. that was definatly your problem. the only potential troubles you may have is if you go through water it could get in the bowl what it is is a vent for air to escape out of the bowl and alow fuel into it.

to clean jets correct you can soak them in carb cleaner and then blast through it with an air compressor. just be causious the jets fly off like little rockets if you are not holding them well. I usually finding a good long spray into the jet out of a carb cleaner can works just as well.