I have an '81 that's my daily and an '82 in the shed that's become a parts bike. Obviously the are different models but they have a lot of the same parts. Just wondering what the differences are with the engine as they look slightly different but not by much. I'm mainly interested in the valve cover, head and block compatibility. Any info would be greatly appreciated!
The main differences are in the cylinder head.
The 81 head has rounded fins and cam towers and a mechanical tachometer driven off the exhaust cam.
The 82 has angled fins and cam towers. Meaning the valve covers are not interchangeable. The 82 is a electronic tachometer so there head is not machined to accept the tachometer drive mechanism.
The cams are the same grind, only the 82 has no tach drive gear machined in it.
The cylinder blocks are only cosmetically different with rounded or angled fins.
I believe the rest of the motors are identical between the two years, but I'm sure other members will remember any other differences.
