Carb Problem?

I have a 2007 yz450, put in the JD jet kit, and Zip Ty fuel screw. Just bought a 2009 yz450f, and put the carb from my '07 into the '09. First ride on the 09 and the bike will stutter at lower rpms, and runs good with the throttle all open. 2 questions:

1: There shouldn't be a problem putting the 07 carb into the 09, right?

2: Could it just be fuel screw settings? I shouldn't have to re-jet it right?

Thanks in advance!

do you have different mods on the different bikes or are they both stock

Did you move the TPS on the carb that is on the bike now?

Which JD needle and clip position?

Whats the engine run like at 1/8, 1/4, 1/2 throttle?

Best idea is to try adjusting the fuel screw out to a max of 2.5 turns out. If that doesn't work you may need to go one size up.

Edited by alligatorman

Both bikes had stock motors, only difference is the 07 had an FMF pipe, and the 09 has a pro circuit. TPS was not adjusted when changed. In terms of 1/8, 1/4, 1/2 throttle, all I can say is that the more open the throttle the better it runs.

I'm going to play with the fuel screw and see what that does. Thanks guys!

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