Does anyone know what the true top speed of the 400ex? Also, how much HP can you get out a completely modded engine?

 

A stock 400 can go anywhere from about 63-66 mph and they have about 27.? hp out of the flywheel. I have read that someone on here has i think a 505 kit in it and boasts 82 mph, but I dont know any h/p facts. I would guess he is at about 45 hp.

 

Read my signature, mine does 85 now with new sidewinder 16/32 gears, it is geared ridiculously high and is only good for highway riding.My motor makes around 38-40 hp is my guess, fully modded is like 50, last year in dirt wheels they had a turbo EX makin 60 horse!!