Does anyone have info / comments on doing this ?
Thanks

 

do a search on this topic it was brought up before. Prepare for a really vibrating experince. Problems are frame cracks, motor mount cracks, custom pipe is 300-400 dollars and if not installed properly will crack.

Will a 500xl or 600xl 4 stroke work in this setup??

 

You could put a CR650 motor in it... I 've heard that they'd vibrate your hands off though..

David

 

There's a guy that chats in the chatroom that put an XR600 motor in an R frame and raced the baja....he cracked the frame pretty bad

 

I agree that a dirtbike engine without counterbalancer would vibrate BAD! But you could reduce it a lot with anti-vibration steerin stem, steering damper, and afew other steering mods. The kawasaki team is running the KX250 in their quad without the counterbalancer and said its noticable but not overly terrible.
It would be freaking fast, thats all I know.

 

If I remember right the KX250 Kawasaki is using in the KXF250 has a crank mounted counterbalancer.

 

If it does, this has been added this year. Dirtwheels first ride of it said it doesnt have one and he used a steering stem and pro-taper bars to reduce it.
If they can add a counterbalancer to the crank on an engine without one, couldnt that be added to the KX500 or CR500 as well?
I have a friend planning on doing this conversion with a CR500 this summer, I will let everyone know how it works out when he gets it done. It will be awhile though as he just got his frame 2 days ago and the engine should be here in a week and a half or so.