CR250R conversion curiosity

[MtnEX]

OK I am curious about this conversion right now.

I think I might be able to get ahold of a CR250R donor if things work out.

How big of a deal would this conversion be?

[jcs003]

service honda does it, but they have their cr counterbalanced. i did one with a trx250r motor.


here is my thread:


http://www.exriders.com/vbb/showthread.php?s=&threadid=395940

[TRXRacer1]

For installing just a CR250r motor you'll have to deal with the obvious like mounts, rear kick, rads and intake. Exhaust could be a trick. If you're getting a donor bike you'd have all the electronics you need. Not that it's a big job but it will take time and money to do right.

If I was going to do it Honda style I'd get all complicated. The trick and tricky set-up is a trx250r bottom end with a cr250r top end. Takes a little fab work but you get forward kick, a counter balancer and a modern powervalve. It's something trike guys have done so you'd have some help out there.

My ultimate ride (today that is) would be a 450r chassis with a KTM 300 w/ electric start. Not to mention enough goodies to max out a card or 2. Would be nice to have a pinger in the garage again but suppose I better catch up on the bills first.. ;)

[jcs003]

Originally posted by TRXRacer1
For installing just a CR250r motor you'll have to deal with the obvious like mounts, rear kick, rads and intake. Exhaust could be a trick. If you're getting a donor bike you'd have all the electronics you need. Not that it's a big job but it will take time and money to do right.

If I was going to do it Honda style I'd get all complicated. The trick and tricky set-up is a trx250r bottom end with a cr250r top end. Takes a little fab work but you get forward kick, a counter balancer and a modern powervalve. It's something trike guys have done so you'd have some help out there.

My ultimate ride (today that is) would be a 450r chassis with a KTM 300 w/ electric start. Not to mention enough goodies to max out a card or 2. Would be nice to have a pinger in the garage again but suppose I better catch up on the bills first.. ;)

FTZ does the cr top end conversion and its about 1800 dollars. you can get a powervalve cylinder for a trx and be done with it. but you can see on my thread the mounts are the only big issue.

[TRXRacer1]

Originally posted by jcs003
FTZ does the cr top end conversion and its about 1800 dollars. you can get a powervalve cylinder for a trx and be done with it. but you can see on my thread the mounts are the only big issue. 1800!!! Holy hell. Does the price include Vaseline? That's the snowmobile style pv jug. You can bolt on a CR250 pv top end to a trx bottom but you need to do some custom work to hook up the linkage internally. In the end a great setup and a hell of a lot cheaper if you're a do-it-yourselfer.

[JOHNDOE83]

Ive wanted to do this for a while, but after some research, a cr500 conversion is the same price!!!!

[MtnEX]

Wow, I am sure glad I asked instead of spending a bunch of time searching and reading...


I would have never thought about the counterbalance thing... and I might not have found that out just reading.

So the CR is not counterbalanced?

So that is going to vibrate crazy?
How does it get by without it on the bike?

And are there other things that the counterbalancer would help with on an atv... like more rotating mass for more stall resistance?


Gotta go look at those mounting pics....

[jcs003]

a bike gets bye with less connecting points and heavier frame tubes. but a bike does vibrate alot anyways.

[400man]

ive done a couple different 2 stroke hybrids (blaster motor in a 250r frame and a banshee motor in a 250r frame look em up on youtube ;) ) and in the end they are not worth the time and effort it takes to build em. the MAIN problem with making a good 2 stroke hybrid is getting the exhaust setup correct, thats what killed my 2 projects and made em run like doo-doo.

i'd say just lok for a deal on a good used trx250r and be done with it.