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New Top End Bike Has issues starting/idling

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Hey guys I just did a brand new top end on my 08' crf450r and I can get it to start but I have to hold the throttle partially open for it to start. And when I got it to start it had a hard time idling until I turned the idle screw up. Also, whenever I would blip the throttle when it's started it would stick in the higher rpm range for a little while and gradually slow down to a slower rpm. Please let me know if you guys have any idea of what's going on. I messed with the accelerator pump a little while I had the bike apart so that when I got on the throttle hard it wouldn't hiccup like it used to. I didn't do a big adjustment but maybe that's what is causing these issues. 

Edited by Bigtyme07

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Ya check the pilot jet for cleaning. They can gum up fast if you dont drain the gas.

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 As mentioned above:

- replace (don't clean) pilot jet, and possible  clean the passage above it with fishing line

- put on a fresh fuel screw oring

- set you fuel screw at 1 turn out.

- drop the idle as low as it will go

- now raise the idle with the fuel screw.

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We redid the valves on my brothers bike a couple weeks ago and this same thing happened. I read on here that its most likely a clogged pilot jet. Turns out that he was somehow missing his fuel mixture screw on bottom of carb. Replaced this and seems to be fine.

Now I just rebuilt the top end on my 07 and can't get it to even kick over!!

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