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2003 CR250 no pwerband

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Hello,

im new on here to post but have read a lot of useful information over the years.  I recently bought an 03 cr250.  The bike was very sluggish at the top of each gear, basically didn't have a strong powerband at all.  I grew up riding these in the 90's.   I recently rebuilt the top end with new piston, rings, cylinder and gaskets, changed the rc cables and adjusted them tight (new valves came with new cylinder), added an air striker carb with factory jetting (I'm at 200' elevation), added new air filter, reused the force reeds (they looked ok), added a gnarly pipe and muffler and the bike runs exactly the same and has no strong powerband whatsoever.  Starts right up, idles perfectly but gets to the top of first and second and basically bogs down.  It's just not crisp at all.  Nothing changed after adding all of the above. The rc valve does rotate back and forth with the throttle and seems to be working fine.  The only thing I kept original were the reeds, the entire low end and the servo motor.  Do I have leaking crank seals?  Any help would be great thanks.

Edited by Sbdrums24
Miss spelling

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What is your jetting? Did you do a pressure test of the engine to ensure it is air tight? Anything more than a 1 psi drop per minute is unacceptable. Even that is a lot. I think your jetting should be something like 42 pilot and 172 main for a good place to start.

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Thanks for the tip... I bought new reeds and found 4 problems.. the needle was set in the #4 position (I moved it to the #3 position), the reed cage was upside down so the intake didn't line up with the carb (flipped it around), the white plastic ring on the needle spring wasn't seated (fixed that) and there was an additional gasket at the reed cage/carb boot connection (removed the extra gasket).... bike runs like a bat out of hell now! Thank you... it has a 175 jet in it now which seams ok. I'll pick up a 172 though. Thanks again.

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