If I put a KN filter on my Rancher AT, will I have to rejet, and is it worth the expense. I am not looking to do anything, but maybe have a permanent air filter I can wash and reoil. But wondered if this would cause me to have to rejet.

 

The filter itself will lead to no performance gains, and you will not have to rejet.
The only advantage will be better filtration, if you add a prefilter. Unless you add
a good pipe, there will be no change in flow thru the engine, and no gains. But then
you will have to rejet.
A filter. jet kit and pipe will give performance gains, but not a lot. Noticable yes, but on the
Dyno not much difference.

 

I'd stick to a foam filter like a uni filter,there cheaper and safer