Need way more top end.

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#1
I just picked up a 2003 CR125 and I rode it today and the motor kinda sucked. It did not have any bottom and not alot of top. I really want more top, I don't care about the bottom end that much. It has a pro circuit exhaust and silencer. What can I do to get more top end?
 

Rich Rohrich

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#4
NCrider26 said:
I adjusted the air screw, but I am thinking of going one richer on the main jet.
Air screw straight to the main jet, sounds like a logical jetting sequence.:whoa:
 
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#5
Rich Rohrich said:
Air screw straight to the main jet, sounds like a logical jetting sequence.:whoa:
No, he asked if it was jetted, I said I adjusted the air screw and it runs good and clean on the bottom. I want to go up on the main jet for some more top end.
 

Rich Rohrich

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#6
Yeah, it must be me who doesn't get it. ;)
 
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#8
the clip on the needle affects mixture from idle to half throttle. main jet affects mixture from half throttle to full throttle.
 

Rich Rohrich

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#9
NCrider26 said:
but anyway will going up on the main help my problem?

Until you assess the engine condition, the power valve function, and a few other things, you won't even know what your problem is, let alone know if a main jet change will help.
 
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#10
take the bike apart, to a top end if you need too. It could solve all of your problems right there. Give both the carb and the powervalve a good clean out. Then, if the problem still persists, move onto jetting.