Headpipe And Jetting

[maynard22]

I have a t4 procircuit slipon right now and a friend is giving me a fmf headerpipe and i am wandering if i will have to rejet my bike, and will this give me any noticeable power.

:devil: :devil: :devil:

[cals400ex]

what elevation you at? what jetting you running now? air box lid on or off?