how can I make my raptor 250 to accelerate faster

and modifications for my 150cc atv I want it also to acclerate fast

 

For the Raptor add an exhaust air intake kit and have it jetted, That will add a couple of HP. Change your sprockets. I believe you would want to drop a tooth in the front and up 1 in the rear. Someone please correct me if I'm backwards. The only downside is you will lose top end. You can't have both.

Is the 150 a chinese quad? Might be hard to find parts.