What parts on '81-'82 250R will fit on '83-'84?

[erv900rr]

I just bought a pretty decent '83 Honda ATC 250R :-D that came with (2) '81 "parts" 250Rs. The parts trikes are pretty much disassembled including the motors. I'd like to get rid of these parts trikes but would like to keep whatever might be used on my '83 if needed.
I can tell the bodywork & tank is different. What about the motor parts (there are 3 extra cylinders) & exhaust? Anything worth keeping off these '81s? :?:
Thanks,
Ed

[nitekrawler]

If you have a master cylinder for the '82 250r Atc, PM me 8) I am interested.
My son's '82 250r has '84 forks on it (not the pictured Atc)

[plumber]

the motors on 81-84 are identical with the exception of color and a few small items like the shifter splines are longer on the 81-82s which are easy to change out if you have to.so the x-tra jugs you have will fit your 83 the only other things that will interchange are small stuff like the hubs will all interchange because the axle splines are the same just the bolt pattern changes. The exhaust are different from the 83.

[86waterpumper]

the 81 through 84 motors are NOT the same. They had different porting, different compression, etc. They may bolt up and work, but between 81 and 84 the 250r gained nearly 10 hp, so bolting on a 81 topend to a 84 bike would hurt performance considerably.

[plumber]

no there not exactly the same i own an 82and 84R and ive ran a black top on a red bottom and a red top on a black bottom and havent notice any signifigant power loss or gain either way. So keep the jugs Ed they can and do work and with parts getting harder and harder to find you will be glad you kept them.