Can someone tell what the purpose of shimming your carb needles is? What benefit does this provide? I just installed a new Muzzy exhaust on my KFX 700. Should I shim the needles when i jet it? Thanks

 

The purpose of the shims is to correct a low end(just off idle) stumble of the prairies. If you are at a standstill and you jam full throttle, if you feel just a quick hesitation or burble you should add the shims. I put in .030" shims with a stock pipe and I backed off my air screws 1/4 turn. Mine runs perfect like that at the moment, I hope it stays this way when the hot weather gets here.