I have a 2005 honda 400ex, which is by far the best ATV i have ever ridden or owned. i ride mostly in the woods, and in local sand pits. the power and its delivery i get from my 400ex is great in the woods however, is there any way to make it rev faster? possibly lighten the flywheel? or what can i do?? i dont want it to rev as fast as a 450r, although it would be nice. anyways let me know if anyone has successfully done this or heard of this. thanks

 

Lightening up the flywheel is always the easiest way to make an engine rev faster. I am guessing you already know that if you lighten the flywheel it will be easier to stall. I am not sure of anyone who has done this to a 400EX, but there is probably someone on here who has went down that road. Even though the revs would be quicker, I doubt your engine would rev as fast a 450r (or any 450 for that matter), because of the 450s having a very oversquare engine(the bore is bigger than the stroke). Good luck with your choice.

 

change your sprockets!!! You won't go as fast on the top end, but it'll rev faster. I'm assuming you either need more power or you need to get some tire speed when taking off in the sand. Either way, chainging your sprocket/s (rear bigger or front smaller or both) will give you more power, making it rev faster, which will in turn let you wind up and bang another gear sooner in the sand getting more tire speed.