what about a 250r swap? i was thinking of doing that to my 400...but it doesnt look like theres even room for the pipe, which ones will work? thanks

 

The differences between a YZ and a WR are mostly timing and gearing, plus the wr has a heavier flywheel than the YZ stock.

I am actually looking for a WR for my own conversion, instead of the YZ .

The power is just almost too much for me to feel comfortable with. You must treat the throttle with respect, or you will be on your head.