started sputtering

[insaneracin2003]

i went riding sat (mx) i have an 01 400ex with just a HMF slip-on and jetted 160 on the main with a UNI filter and stock airbox.
while i was going through the gears it started to sputter in high rpm's,i thought i reached my rev limiter so i didnt think much about it.
on my second time out that day,the same thing happened but it started in the lower rpm's like it was starving for gas,i just filled up with 93 octane which is what has been run in it ever since it was bought,air filter is also very clean
anyone have this happen to them and was it an easy fix or should i remove the carb and clean it reel well?
you guys have helped me a bunch in the past so i figure i would ask the pros on here for advice:D
thanks....Paul

[zephead400ex]

Check your main jet. It might have rattled out.

[cals400ex]

first, i would clean the carb out. while you have the carb off, i would change the mainjet to a keihin 152 or 155 at biggest. this should solve your problem.

[insaneracin2003]

thanks guys,very much appreciated!!!!