Hey guys, I just bought a ct racing pipe for my 03 KfX 400. The original jet I was using was a 130. How many sizes up do you figure I'll need to go to get the right fuel/air mixture. By the way, I will be running it without the air box lid. Thanks

 

when i put my pipe on i had to go to a 165 and a 25. the fuel screw will have to be ajusted as well ,do not turn it out more that 3 1/2 turns .

 

I didnt even touch my jets or anything when i put my muzzy and k&n on. A/F ratio still measured at about 14.7:1 on my gauge before and after the pipe and filter.

 

really ,and what year ltz/kfx was that ? open air box to ?

 

So i tried all sorts of jets, a 147 main jet and the air screw is set at 3 1/2 turns, it seems to work pretty good. I'm gonna do a spark plug color test so I can get it right on. Im sitting at about 2500ft here in Alberta. You guys think a rev/cdi box would be worth the investment?