If your 400 is stock, the 14T is a good move...off the line will be quite a bit faster, but you will have to shift each gear sooner, and you will lose about 5mph of top end speed.

If you're running a modded 400, go up to 16T, and drop a couple in the rear. My 416 has the power to pull this gearing, and it keeps me right with Raptors, DS650s and 250Rs, off the line and right thru the top speed. Plus, due to taller gearing, I can hold gears longer before hitting rev limiter.

 

yeah my ex i pretty much stock for now all it has is a Yoshimura slip on
and a K&N power kit with no air box lid but i plan on putting a 426 kit on it then i will probably go back to my 15 or to a 16 .

 

Can you fit a 20 on it?

 

DON"T, it really makes it suck!! i race'ed a 13t sproket 400 and i SMOKED it!!

kc

 

there's not enough space to fit a 20 tooth front sprocket on the 400EX.

 

wow i am very very happy now with the 14tooth mod. i rased my buddys full race 440ex runing on race gas with 19" tall tires and i think he had a 15tooth and i kept right up with him up to the end of 3rd gear then the extra power of his quad started to do its damage and i pulled away but i am very happy with it and i would recomend this mod to anyone.

 

with the 14t did u have to take a link out of the chain

 

nope just had to tightend the chain up .

 

ok thnx oh and thanks for the good tip

 

its not just the power. put that 15 tooth back on and race him again. he won't pull on him in the upper gears nearly as hard. you are killing yourself with the 14 tooth sprocket in a DRAG race unless it is a really short race.