87-89 crank and piston with 86 cylinder?

[badtothebone250]

A friend of mine has a 250r and is rebuilding it. He has what I believe is a 85-86 cylinder but has purchased a 87-89 crank and piston. Any reason this will not work?

[fearlessfred]

the rod is 5 mm longer on the 87 thru 89 crank so you will need a spacer plate and run the early piston. im sure other on the site will comment and have more info

[mx91a]

No spacer plate needed if the piston is for 87-89 engines

[fearlessfred]

Originally posted by mx91a
No spacer plate needed if the piston is for 87-89 engines dont know this for sure,but wouldnt there be some power loss from running a full skirted piston with an 86 jug .

[fearlessfred]

and are the ring locaters in the same place on the different years

[jhtrx250r]

Ring locaters are in a diffrent spot.
Eventualy rings will snag if a 87-9 piston is used in a 86 cylinder.
I would run a spacer plate and a 86 piston that will work fine.

[86 Quad R]

Originally posted by jhtrx250r
Ring locaters are in a diffrent spot.
Eventualy rings will snag if a 87-9 piston is used in a 86 cylinder.
I would run a spacer plate and a 86 piston that will work fine.

Not to mention that the 87-89 skirt isnt designed for the "opened" port configuration the 85-86 cylinders have. i'd not reccommend....