i have heard of people putting cr 500 motors in 250r's and i have a 89 cr500 and i am lookin for info on how to go about putting my motor in a 250r or 400 ex.i am way more confident on a 4 wheeler and would like to race them.anyone with sights or info about this or places that make performance parts or do porting for them or anything let me know.it's already piped and jetted but in a 4 wheeler i will want more power.and can anybody let me know if they alow people to race 500 cc 2 strokes for atv raceing?

 

One little piece of advice for you......Dont do it.It will vibrate your teeth out.If you don't believe me,ask DaBeechMan.

 

I am in the same situation. I also have an 89 CR500. It needs a rebuild, but I have been playing with the idea of putting it into a quad frame. Why is this a bad idea? What makes it vibrate so much and is there a way to fix that? If anyone can point me to some more information, I would appreciate it.

2-Knee

 

The problem is that the cr500 engine is not counterbalanced and is just not designed to work in a quad frame.It will make awesome power but you will be picking up pieces all day that vibrate off.That is if you can stand to ride it that long.I know this from experience and there have been quite a few posts on this subject.Do a search and you will see that others have had the same experience.

 

don't do it. even people that have em advise against it. its fast but it sucks to ride from all the vibration, and its always breakin frames and rattling bolts out.

 

I have an 85 cr500 motor installed in my 85 suzuki lt250r. you can look at pics on my profile if you would like. It does have some vibration mostly at an idle. You will want to lock tite your bolts and use locking washers. I ride mine all the time and the vibration doesnt bother me at all. The only time I notice it is when im sitting at an idol. I also know a guy who put one in a banshee frame and he loves his also. He hasnt ever complained about vibration either. I have read alot of posts in here on the subject and they will all tell you that you cant ride them very long or your teeth will rattle out. Maybe some atvs or the way they were installed will cause problems but mine hasnt given me any problems, plus the power on the 500 is so much nicer then any other 2 stroke. You have tons of low end power unlike most two strokes and they are very fast also.

 

You say the vibration isn't that bad. Did you use rubber motor mounts, or modify the motor to reduce the vibration? Or did you mount the motor directly to the frame? If so, did you beef up the frame any, and has it ever cracked?

 

It is mounted solid to the frame. I didnt do the install I bought it this way but as far as I can tell the frame is stock. They did fill the accessible parts of the frame with expandable foam and they an aftermarket steering stem that has vibration dampers in it. So far I havent had any cracks in the frame. I did have one motor mount bolt on me and I didnt get it changed so It caused the others to break also. I have all new bolts in there now so far so good