i want to put a pipe on my 400 do i need a rejeting,and also what is a good pipe for my machine?is the pipe hard to instal properly? thanks for any advice.

 

i bought all of my mods and i rejetted just in case. bone stock my kfx400 ran a little under 75. i dunno what it runs now tho

 

yes you should rejet.
I like my CT pipe,fits good, looks good, not to loud.
Most pipes give about the same power.
Not to bad to install, bigest problem is geting the float bowl screws out to rejet.(impact screwdriver)