YFZ hybrid

[Throttle Jockey]

My son started racing MX this year in the youth class on a Raptor 125cc. He is already in need of a bigger bike. I would like to build a hybrid 250 for my sons next step in ATV racing. I was looking at installing a yz250f motor in a yzf450. Has anyone done this? if so how did you solve the starting problem. It looks like the kick starter will hit the plastic Nerf bar. Are there any recommendations or alternatives I should consider?

[Deuce]

Anything can be done with a little basic fab work.  May want to look into what they did in the golden era of hybrids when they stuffed the 426/450 motors in the 250r and 400ex chassis.  This was in the early 2000's pre yfz and trx 450 days.

Fenders typically got cut to clear the kicker, sometimes an extension would be made to push it out, or a smaller kicker from another motor would be used.