Quick fix?

[FutureRacer]

On my 2002 400ex i have a white bros slip on pipe and a ka nd n filter, i had it rejetted by a very good mechanic, but i think the main is a lil off, I believe he put a 155 in it, but when i am WOT in 5th, itll sputter and die down, all i have to do is stop shift to neutral, and it will start right back up. Not sure what to do, is it just a lil off on the main. Thanks, Kelley

[Reggie44]

17 6
It sounds like to me you have to big of a jet. The main jet controls from 3/4 throttle to wide open. Try changing it to a 152, and that should solve the problem. You don't need to take it to the mechanic. On the bottom of the carb take the nut off using a 17mm socket, then carefully reach up in it with a 6mm socket to undo the main jet. When you put the new jet in, make sure you don't over tighten, and make sure you turn off the gas