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Yz250f 09 With fmf 4.1 Jetting help


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I have a 09 yz250f with a fmf 4.1 system with the power bomb and i bought the fmf power up kit and did what the directions told me put every jet i was supposed to and my bike was running lean so i kept going up on the main jet and the plug still says lean. my settings as of now are

Needle - 5th notch from the top

Pilot Jet - 46 I think

Main Jet - 190

Leak Jet - Stock

Fuel Screw - 2 1/2 screws out

Please help me out i just cant seem to get it right what else should i try

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and the plug still says lean.

Please help me out i just cant seem to get it right what else should i try

Reading the plug is not how it's done anymore due to the current formulation of gasoline.

REad a few threads on how to tell the difference using your "butt dyno".

Also, the instructions given are a baseline and not an absolute. Testing is the optimum way to get the most out of your bike. William1 has several threads on the best how-to.

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