i know this is a trike board, but the motor is the same...

[turbo]

ok, this might make some people mad, but i have a question for you guys on my 01 400ex, it runs great from idling till full throttle, until i start riding it hard like i do when i race, the problem is that it will start cutting out, like it isnt getting enough gas, i have already taken the carb apart and cleaned it, drained all the gas in the tank and put new in, and cleaned all the gas lines, the air cleaner has also been cleaned.
when i am in the ditches and hitting jumps in about 3-4 th gear it will all of a sudden just die, it will idle but wont let me hit the throttle again with out dieing for about a minute, the funniest part about is that it wont do it until the motor has been running for about 20 minutes at high rpm's and then will continue to do it until i quit riding. oh, the spark plug also looks fine, has that nice sandy tan color to it, and blue spark, sooo my question is, is my problem still in the carb, or could my timing or valves need to be adjusted? or bad rings? im completely out of ideas, and most things i can figure out, so im hoping a 350x guy or someone with amotor like it or a similar problem can help me out

[Fuzzy]

Sounds like your float is set wrong or sticking. Or something is stopping gas from getting through the petcock in the tank. Not letting fuel flow. So it cant replace the fuel fast enough to keep up with what you are burning. So after a few minutes of riding it starts slowly starving for fuel. So it will only idle and as soon as you hit the gas it gets to much air and not enough fuel and wants to kill out. So i wold pull the petcock out of the tank and clean it out good. And also check your vent hose on the tank to make sure it is clear and getting air. So that you know the tank isnt just airlocking and not letting fuel flow. And if that still dont stop it. Try pulling your carb back off and checking your float and seat to make sure the float isnt sticking in the off position. Or maybe not opening enough to let gas in fast enough. Good luck.

[dads]

May be a bad vent in the gas cap when it dies losen cap re tighten and give it gas if that works you have a bad cap.

[turbo]

ok, im still stumped, i took the petcock off, and there was no dirt, or residue on it, but i cleaned it any way, the float also isnt stuck, and i cant adjust it as it is plastic, but it has full range, and is in the specs for what the book says, i took the spark plug back out, and there is a small amount of carbon buildup on it, but it has been in the for a year and still starts fine, and wouldnt the carbon buildup mean that it is running rich, so its getting enough fuel? whereas if it was white or gray it is running lean and theres too much air and not enough fuel? well if i cant figure it out in a bit, its heading to the shop and getting some hop ups on it as well. any way, thank you guys for your ideas

[turbo]

well, its heading to the shop tomorrow at 9, i know its a sunday, but i have a friend that owns a motorcycle/atv shop and hes going to work on it for awhile and see if he can figure it out, if not, i geussits getting sold and getting either a new one, or a crotch rocket, so well talk to you guys later