1985 Suzuki RM 125 motor swap

EDIT-
Maybe not... the frames are different. I remember the '86 had slimmer, oval tubing at the ankles and that may affect the width of the crankcases. The engines sure look the same but most of the part numbers are different.

I had an '86 and my friend had an '85... they looked almost identical in shape, but of course that doesn't mean anything. In addition to the tubing shape, I remember the '85 still had the actual Full Floater suspension, whereas mine was that eccentric cam link thingy. The bottom of the frame was likely different, so maybe the engine mounting bolts were too.

It might be worth trying if you can find an '86-'88 motor for cheap. I do know the '89 model was 100% different.