Whats the best engine upgrade swap for a 250x?

[2fastandfurious]

Whats the right motor that will be the easiest to upgrade in a 250x? Will the 400ex engine fit in pretty well? I have a 300ex head now and so i probably want to go even to a 2 stroke if possiblile......... Any motor cylce 4 strok engines???
-Ben

[TheX1992]

the ATC 350x practicly bolts right up. its what most people do to their 250x's. www.powroll.com sells mounting kits for around 70. the exhaust will be different but i think if you can weld you shouldnt have to spend 460.00 on theirs. just use the 350x stock one and make a new bracket it might work.

[300exazzkikr]

You want some real power get the 350x. You won't regret it, I've done the conversion and i know a bunch of others that have done it, you can probably do a search on how to do it and it's explained thoroughly. I'm doing research now to build a frankenstein motor for the 250x/300ex. I don't want to spill it all out, but it'll fly and be everything you've ever wanted from a motor.:devil

[BLURR250X]

300azzkikr,

Did you use the powroll kit when you did your 350X conversion or just do it on your own?Which is better the kit or just do it yourself?Can you pm me all the steps that it takes to do one?thanks