How do I know what year motor is in my YZ125 ?

I just picked up a 1990 YZ125 that is really rough shape , bought it as a project. The seller said he was pretty sure the motor in it was from a 93. How do I confirm this , anything in particular to look for ?

or does anybody know if most motor pats for a rebuild (gaskets , piston , cylinder) are the same on a 93 or 90 motor ?

What is the engine number?

the number on the cylinder is 4DB00

That would be a 92 cylinder.

awesome , thanks for the help

I'm beginning to think that this isnt a 1990 yz125 at all , the 90 muffler and the 90 rear fender doesnt fit quite right . the VIn is JYA3XJW07hA009339 , or maybe JYA3XJW07MA009339 , hard to read. Any way to tell from this VIN ? thanks again.

Edited by baisleyde

JYA3XJW06MA40XXXX is a vin for a 1991 yz 125

if there is 3xj on the right hand side engine case its a 1991

post a pic of the bike?:thumbsup:

Edited by yz125 91
link wasnt working

I will have to wait until i get it put back together to post a pic , but from the reasearch i have been doin most parts between the 90-92 are interchangeable , or you can make them fit with not too much work. I'm now certain that its not a 90, and the motor is a 92.

yes i have a 1991 yz 125 and almost all parts from 90-92 interchange

so I was rebuilding my forks , and noticed the only adjusters on the forks are on the fork caps , nothing on the bottom. was rebound the only adjustment on YZ's of this year , or does this adjust the compression damping ?

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