300ex sputters a 3/4 to WOT

[rg22764]

what could cause this if not Jetting i am at my witts end on this.

[2004exrider]

3/4 to full throttle is a main jet problem. Your either to lean or to rich. Take your air box lid off and see if it helps any, if it does your to rich lower the jet size if worse go up a size or two.

Jimmy

[Iliketogofast]

Word.

[bwamos]

Originally posted by rg22764
what could cause this if not Jetting i am at my witts end on this.

Aye main jet issue.

What modifications do you have, and what main jet are you currently using?

[rg22764]

Only mod I have is a FMF Powercore4 complete exhaust and have a 125 main jet in it now.

[300exOH]

Sounds like you are lean on the main. I would try a 128 or even a 132 main jet and see if it helps.

[rg22764]

Ok tried a 130 and 128 main jet left the 128 in seems to run good. I guess its just hitting the rev limiter and that causes it to start sputtering out then i shift and runs great till it hits it again. is there a different rev limiter i can get to help with this?

[300exOH]

You might be hitting the rev limiter. You can get your stock CDI modified to have a higher rev limit or no limit at all. There are also aftermarket ones available too.