2002 yz426f carb help please

just got a msr mixture screw(just like zip ty) and a hmf performance silp-on pipe(not fmf). they said to run a 165 main so i did, but when i am going about 10 miles per hour in second gear it rides like a 2-stroke, crack the throttle half way and bike takes off slow,then when rpms are high it rides normal. any help would be appreciated. i also line in the city so cant go for test rides that easily.


Probably not the main jet. What is your idle mixture setting? Put it at 1-3/4 turns out from all the way in.

That is where I would start. It may also be your clip setting, or even problems w/ your hot start or accelerator pump.

Check your idle mix and get back to us.

Hope this helps.

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