How does the big bore kit compare?

[Lukeidiot]

My friend's bike is currently in the shop getting his 440 kit installed.

I have a mildly modded 400ex (jet kit, stage 2 cam, sproket, k&n air filter) and i was wondering how much faster the 440 kit would compare to a 400ex, and a 450r.

thanks!

[CDCHONDAS]

what all is he getting, just a 440? if so then he isnt gonna gain alot, once you get air to them though they will wake up and run

[DF400ex]

It won't make it any faster, just accelerate faster. If you want top speed you need to change your sprocket size. The 440 kit will give you the power needed to go faster with the deifferent gearing. It all depends on your riding style and what you are looking for.