Topic: CB750 early crank cases

[ttr400]

I have a set of 69 -70? cb750 NOS crank cases, how do i figure out what year these might be? they are unstamped and are painted a light grey colour. were the cases on all years painted from the factory?

many thanks
Kevin.

[bryanj]

Yep all painted but supposedly silver. VERY early cases had a different number of clutch cover bolts but I aint up enough on the 750's to say how many or when

[ttr400]

Thanks for the info, I had a closer look at the colour which could be silver but not very gloss.

Ok all you 750 guys, how many bolts on your clutch covers? and model year.

Thanks Kevin

[Sterling2]

 Sandcast cases have 9 bolts in the clutch cover. Diecast cases all have 10.  Real early sandcast cases also have the month and day cast into them.  If you have a set with no serial numbers and it does not appear that the numbers were ground off, they are most likely a set of diecast cases made in 1970 used by a dealer on a warranty claim.

[Clyde]

The size of breather/oil return on the back of the crankcase changed in later cases (74?) to a larger size.
K7/K8/F2/F3 used a bigger output shaft bearing.
Honda put an extra bolt on the post sand cast cases due to a supposed oil weeping problem