85 YZ250 Cylinder interchange

Does anyone know if another year of cylinder will fit my 85 YZ 250? Will an 88 fit? Thanks for any help!

i know 86 to 98 are the same bore, i have an 86 yz250. theres nikisil cylinders but i believe they are later like 93 and up.

Should be like '84 thru '87 that would work becareful and check that was when yammie couldn't decide on if they wanted to use head gaskets or oring setup.

My 86 has o rings and 87 is o rings as well

So, an 88 won't fit an 85? Does the head have a place for the o-ring or is it the jug? Or both?

Actually, will an 88 jug and 88 head fit on an 85 case and rotating assembly to eliminate the o-ring problem?


I can find a decent 88 head and jug with life left in it but so far an 85 setup has been elusive.

88 Jug is a different shape it wasn't mentioned in tech specs but that was the first year yammie also went to hard platted cylinder walls.

The jug and head have grooves for o rings on 86-87. 86 to 98 was all the same bore and stroke... which is where alot of people get confused.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now