My buddy has an RM80 and bought a book giving extremely detailed info on how everything works including wiring diagrams. This Link leads to your model.
You might also want to check on Ebay, you can get all the parts you can think of for your bike from there and probably manuals too.
Try this website www.themotorbookstore.com/rmtwinshoc19.html
Haynes manual
Yes, You can. But you have to bore the Engine Bore bigger to match the piston. The Guage can be located at any Autoparts store.
1976
Go to bikebandit.com and look up engine parts. On the bottom, they have the engine break down diagram along with part numbers. They also have other diagrams, such as brakes, wiring, misc.
If youre not a moron and you know basic electrical wiring sure..
Use the microfiche on Bike Bandit. www.bikebandit.com
malaysian ringgit (RM)
Will a 94 rm 125 engine fit on a 2000 rm frame?
Rm-glutathione
RM-X96
no
rm 1,900,000