horses, air filters, and speed

[DangerousDean]

How mcuh horses does a stock 400ex have?


What does a airfilter do ( like a after market like a k&n) would it be a good upgrade?

and whats the topspeed of a stock 400ex?

[H_W]

This has been asked before, many times. Almost to many times to count. But to answer your question, a stock 400ex has about 26 hp and the top speed is around 65 mph. And an aftermarket air filter, like a K & N or Uni, will let in more air than the stock one. This along with a good pipe will add a noticable gain in power. Yes it is good upgrade, it is usually one of the first things most people buy.