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Difficulty starting, won't idle, power loss

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2008 crf250r. Just installed new gaskets for top end and new rings. I also adjusted the valves since the exhaust side had tightened up. I cleaned the jets in the carb prior to the top end work (which took about 3 weeks) It is still as difficult to start as before and i have to give the throttle a slight twist when i crank for it to start up. It will not idle and feels like it's significantly slower. I didn't ride it much before the top end work so maybe I'm just used to my 450 but it seems like it's sluggish. It doesn't pop at all though so what could be causing this? 

 

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how tight?  Can you do a leak down test and make sure your exhaust valves are actually sealing?

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lets start at the beginning, you said it did the exact same thing before top end and valve shim correct? How long have you owned the bike? Did this gradually start to happen of one day all of the sudden.? Are you positive timing is correct, timing off one tooth hard to start but will, also would have less power? just a thought.

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So I got this bike a month ago and the only time I rode it was the test ride but it did feel like it had more power then. It was just as difficult to start then and once started and left running for a bit it'd start spewing coolant out the overflow so I replaced the gaskets. I'm 90% sure the timing is correct but it's possible it could be one tooth off. It will still start after 10 minuted of kicking and just enough gas at the right minute. 

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Id probably start with the basics. Did you check cylinder wall for roundness during rebuild? What did cylinder walls look like?  Im thinking if the bike, before your had it, was way overheated you could have head warpage, valve seats burned and not sealing, cylinder deformation.... Find and autozone and borrow a compression gauge, they loan them for free, start by checking compression on cylinder and let us know psi

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Okay so I'm waiting for orielys to get a leak down test kit in, but the past two days have been able to start it right up in 1-4 kicks. It won't idle with the choke off and is very "jerky" even when holding the throttle in a constant position. If that helps...

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any chance idle or fuel screw was adjusted to compensate for low compression on top end. Do you know how to adjust fuel screw? How does it ride? any coolant spewing now?

Edited by eazy230

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I did not adjust it  that i know of but its very possible its out of whack from when I bought it or cleaned the carb. I know how to adjust the idle but Im not sure how to set the fuel screw to the right setting. No coolant spewing, just rides like crap

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