Model Combat 1972 or 1973?

This frame number it is not a combat but 750 commando MK5.

Then again, all 750s after 200.000 had the unhappy 72 type crankcase I am told that needs to be modified to work.

Hi Antonio

According to Roy Bacon's book...

"Matters improved a good deal in 1973 for the final 745cc engines proved to be good ones".

My information is that 1973 started off with engine number 220000, so I'd agree with Francis that your bike is a Mk 5. As for the crankcase, I would bow to Joe's superior experience, however, I can tell you that I've not had too much problem with my bike's (pre-combat) engine (200191).

Peter

Peter,

You probably had few problems if you did not rev it over 4.500RPM for any length of time. If you do the oil disappears out of the breather. The then German importer rebuilt 400 engines in a year. The beasts all blew up on the autobahns.

I had the same phenomenon when I first tried to race a 200.000 series engine. Oiled the whole race track. Did not make me very popular with the other competitors at the time. After that meeting modified the crankcase, no problems since. That was about 15 years ago. We still race that bike.

Antonio:

What is the serial number of the engine?