Identifying a Mark III???

How can one identify a MKIII engine case or crank from the earlier 850 engines? Is there a dimensional difference in either the case or crank?

Mike

Probably the quickest and easiest would be the serial number stamped in the left side. Somewhere in the forum is a list of what serial numbers (frame tag, engine, transmission) correspond with each year.

The primary side crankcase has 4 bolt holes for the chaincase on the Mk3 (3 on pre-Mk3). And of course the S/N begins with 32XXXX or 33XXXX. The crank has a longer snout on the primary side and I believe is wider between the bearings. At least I've been told that using an early crank in Mk3 cases requires much more shimming to reduce the endplay.

The inner primary attaches with four bolts instead of three. And of course the serial #'s starting with Eng.325001 on the case and F-125001 on the frame and it has an RH4 Head. End of crank sgaft is longer too.



Tim