I have a 2001 (red) 400ex, heres the sistuation.
Modified Air Box Lid, Super Trap IDS2, K&N Power Kit, 170 main jet, 14t sproket
I live in Little Rock Ar.

Heres the problem I need more Power. My best friend has a
2000 400ex and his is one of the best anyone has seen. I know for an engine
to get put on a quad it has certain power levels it has to meet after being
built. Well his are above and beyond and spec. Where I ride (South Arkansas)
there are 9 other people who ride 400ex's only one is stronger than his, and thats
because the motor was sent to Nac's to be hoped up.

But Top end, even though I have a 14t sproket we go the same speed, mine just revs all the way out.

Ok would leaning out my jetting help, pick up more power? Also what is required to install a 416 kit?

LAter

 

i heard the 440 kit for the ex is awesome. i heard it beats some modified banshees.

 

$ for $ get the W/Bros. 440 kit W/Racing cam.


you will be top dog
it will also be reliable
even if you dont change the cam get the 440kit

not to be mean it could just be his riding skills and weight makes him faster and that is a fact, two names MCGRATH, CARMICLE,if that is the case then all you need is mooooore hp's like i said 440





350 drag banshee
465 drag ex

 

He is 50 lbs lighter than me (im 190, he's 140)
the things is if I get on his bike I beat him.
His bike is just really really strong.

On the 440 kit, how much would it cost?
Kit? Installed?