I just got a new pipe for my Yamaha Warrior. I got the White Brothers R4 slipon, I would of got the full system, but my stock headpipe is bigger than the one it gave you. Anyways would I have to rejet with a slipon or not? If I have to rejet Im going to buy a K+N filter too.

 

I'm pretty sure that you will have to...

 

OK, thanks, I will just buy a K+N and jet kit then. Anybody else's opinion?

 

Any changes to your air intake or exhaust you should rejet for best performance

 

Rejet, you are leaning it out with the slip on. The Pro Design manifold with K&N is an excellent choice for the warrior and much more reliable than the stock set up.