08 CRF250x jetting question

I have a 2008 250x

Full DRD system

JD jet kit

Airbox cut

R and D fuel pump cover ( leak jet set at 50)

pink wire cut

altitude is 3000-4000 ft

needle red 4th clip

main 165 ( then tried 158)

pilot 42

airscrew 2 turns

Temp 25-35 deg C

This is my problem I have what sounds like a splutter or miss just before top , it is not the rev limiter as that kicks in at top RPM the best way to describe it is rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr( only way on the keyboard)

its like a dull vibrating bark coming from the exhaust , am I too rich , same symptoms with 160 and 158 main .

Please help any advice will be appreciated , bottom to mid is awsome ,no problems there .

Also can someone shed some light on what the bike does or what to look out for if it is running rich or lean .


That's the powerband kicking in.

On my '05 250x with a fmf, I was running a 170 main. Try going to a 168 and then 170 doing test runs to see if anything changes with each adjustment.

That's the powerband kicking in.

Ya right !!!!

On my '05 250x with a fmf, I was running a 170 main. Try going to a 168 and then 170 doing test runs to see if anything changes with each adjustment.

I need to know which direction to go , leaner or richer , do the symptoms I have sound like a lean condition or rich ?

I'm telling ya!

When it goes : "rrrrrrrrrrrrrrr rrrr". that's the powerband

Its more of a stutter , anyway I'm wondering if maybe its my float level , can someone perhaps shed some light on the float height and symptoms of incorrect float height.

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