dies but will start again

[badluckrider]

I can ride my 400ex for about an hour and it will act like it is running out of fuel and will stop, after it stalls it will start back up, as soon as i give it any gas it shuts off. It will continue to fire but as soon as i give it gas it shuts off. The motor is completely stock with a twin air airfilter, which is cleen.

Thanks for any help

[mikeboone]

Check the gas vent tube from top of gas tank; be sure it's attached and the end is free to 'suck air'. Also be sure the fuel petcock is completly in On position. If above doesen't work remove the tank and 2 bolts holding the petcock on. Inspect the reserve tube fuel filter for any debris. I would clean the carb as next step.