02 YZ426 Fuel Screw Setting

I don't have the manual - can anyone tell me what is the stock setting for the fuel screw? I'm guessing it's 1 1/2 turns out...Also, turning it in does what? Does turning it in make it leaner or richer?

Thanks :cry:

Here is the complete shop manual for the 426

426 Shop Manual

The manual states 1 1/4 turns out as the factory setting. Turning the fuel screw (or "pilot screw" as the manual refers to it) in will lean the mixture at low speeds and turning it out will richen it. Start with the factory setting and then turn it 1/4 turn increments until you have it running properly.

Warm up the motor first Now Turn the screw in clockwise thats leaner till it starts to run bad Now start turning it out slow (richer)counterclockwise till the motor runs smooth :cry: If you don't have a ZipTy or scotts fuel screw go get one there only about $25.00

Thanks Satch0922 and YZF450Jack!

Is there a spark plug you would recommend besides the NGK




Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now