2005 TRX250EX Sounds Like It's Hitting Rev Limiter At Low RPM

[John451]

I have a 2005 TRX 250EX that sounds like it is hitting the rev limiter around half throttle. The thing is, it is not the rev limiter. It does have a K&N air filter and seems to run better with the lid off. It has a brand new head, brand new CDI, new piston, rings, stator, and a lot of other things. I am leaning towards the carb because of how it runs with the lid off. It also will not shift in and out of gear when it is warmed up. Most likely an un-related issue. Any ideas will help. Thanks!

[JOHNDOE83]

Usually hittng the limiter early is a sign of being to rich on the main jet.

It will actually stutter instead of fully rev out like a rev limiter.

Once my main jet had fallen out and it did the same thing.

another time, my screws that hold the needle/slide and cable together came loose resulting in the slide not going up and creating the same issue.

check the carb out, im sure its something in there.

[John451]

Yes that is a much better way to describe it as shuttering. I like 2 stroke carb tuning bettert than 4 stroke, the 2's are much easier to read. I'll have to check it out tomorrow morning before work. Thank you very much.

[John451]

Your 400 hybrid looks awesome btw. I think you win the award for the world's biggest expansion chamber! Did you make it?

[JOHNDOE83]

LOL thanks.

The pipe is for a FTZ 250r, big bore, 400cc pilot cylinder.

I custom fabbed it to fit in the cr250 motor.

The pipe is huge compared to the fmf gnarly that came off this bike.

The fmf was a strong midrange pipe but it fell flat on its face in the upper rpm range and had NO lowend, so I went with a bigger expansion chamber.

This pipe hits hard from the bottom all the way to the top with a AWESOME top end and a CRAZY powerband.

In order to get it to fit properly I had to route it differently, thats why the silencer sits so low, Im in the process of trying to get the metal to bend a new one.