87 frame- 89 engine will it work? kx125

[harrisfmly]

I just picked up a 87 kx125 and it came with 2 motors. I can salvage both i believe but I like the 89 better. 89 is just a guess. casing stamped with kx125fe 003365. 87 stamp khi kx125de. I see a motor mount issue in the front other two seem to line up. Exhaust is real tight but i think it will fit. Surely, I'm not the first to think like this. Can it be done as simply as it seems or should i put the time in the 87 engine?

 

[MikeT]

I think the the KX engine changed in 88. The 88 and 89 are similar but the 87 is different. I had an 88 and my brother had an 87. The 89 will be a much better bike (suspension and handling wise) if you can get that one running.

 

[harrisfmly]

The bottom 2 engine mounts line up- sprockets line up-exhaust is weird I really don't think I have the right pipe. Air box is going to have to change. Anybody know if the 89 box will fit in 87 frame? what are the differences?