I have a buddy that just bought a kfx400 and it is time for the pipe jets filter and tires!...I do know that haulers are the best but what size for this bike? And what about the the Pipe, filter and Jet size?

 

I like my CT pipe a lot, performs, looks, fits, and sounds good(not to loud).
I hear good things about curtis sparks pipes also. Most pipes give close to the same performance from a dirt wheels pipe shootout.

I would not get more than 8 paddle. I have sandskateII paddles and they work pretty good. When I drag race I get good enough hookup to take off good, but not to much whare I have to worry about keeping the front down all of the time.

 

Id go with the Yoshimura pipe, heard nothing but greats reports about!

 

yoshi is loud if it matters.

For air filter I went with nossmachine K&N filter setup with outerware. Very good setup, its like pro design but cheaper.