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don250r
02-02-2007, 08:43 PM
have a chance to get my hands on a 9? CR250R power-valved motor($75).
is it worth the trouble to adapt it to an 85 250R?
just wondering........

edog
02-02-2007, 08:58 PM
Got any pic of the motor?

firefirefire90
02-02-2007, 09:21 PM
If its a 92 or something..I have the mounts for it to bolt up in your frame.

max
02-03-2007, 10:49 AM
3leggedog did this conversion a year ago or so. He didnt completely finish it but I think he still has some of the parts. I would PM him.

SYKO
02-03-2007, 10:58 AM
the pv motor will be awesome in the 250r chassis, but the close ratio trans hurts it, it would in fact work great in the trails or short course racing, you can though adapt just the pv top end either with the pv blocked out or a serios machining done to make it work, do a search theres tons of PV information here.

PWK39
02-03-2007, 12:09 PM
Ive been tinkering with one for a while now.I'm using a 89 cr250 motor.85-91 bottom cases,cylinders,pistons,trannys,interchange as long as you have all the parts to make it work.The cr bottom ends are very different than a 250r.You have to make a spacer for the swing arm bolt.I made one out of 1"aluminum tubing 1/2" inside.I had to buy a metric drill bit to get the inside the proper size it's 15mm.I just drilled it out on my dads lathe.you have to cut off the lower front motor mounts off the frame although 3leggeddog said one of them work i think.The frame i have is cracked in the front of the cradle.I just cut the whole thing off.planning on making a new cradle once i get acess to a tubing bender.One problem i have heard of is the vibration cr motors aern't counterbalanced like a 250r so they vibrate bad.I rode a 87 cr250 if you rev it the whole bike vibrated.if you need the spacer I still have some tubing left.Just pm me your addy and I'll send one for the price of shipping.

firefirefire90
02-03-2007, 04:26 PM
I have all of 3leggeddog's parts.

3leggeddog
02-04-2007, 10:27 AM
i did have the cr motor completely in a 85 250r.everything was done,including the pipe.when the motor wouldn't run we pulled it out,and found the bottom end was wasted.bad crank bearings,pv was outta time.so i aborted the project,and threw a 250r motor in it.it can be done,and is not too difficult.

Dirtcrasher
02-04-2007, 05:26 PM
I don't know about the other year CR's but my old 94 CR250 motor was simply awesome in stock form. And it didn't vibrate at all, whatsoever - nada. Maybe they had a CB by that year??