are all the 650 cases the same?

i am never happy with an engine when i'm done with it.
so i am now in the middle of doing the 650 again and i have a question for the experts.

are the cases the same?

the first motor is a 77 kz650 and the second is a 81 csr650.

i know the cam chains are different but here is what puzzles me.
the 750 cylinder i have fits right in the 81's cases but not in the 77.
are all the internals the same and all i really need to do is swap cranks or is there a big difference?

or if the cases are the same, can i just change every part from the earlier into the later?

also, will a gpz750 tranny fit in 650 cases without to much mods?

i just figured i'de ask before i screw myself.

The cases are pretty much the same. everything will switch over. If you keep the 77 head you'll just use the 77 crank. I've done it before.
Mark

I've never done it, but simply wanted to put a 1978 stator setup on a 1977 engine and the cases dowl setup was reversed on a 1978 vs a 1977 so the stator covers and stator could not be bolted up. Of course this is not a big deal, you'd either have to drill the stator cover or the cases to enable the swap, but this is only part swap #1. The cases are probably real close but in typical Kawasaki tradition there will be some differences.

I recall a discussion on putting a 6 speed tranny (is this what the GPz750 has?) into a 650. The kickstarter and gearing needs to be removed, and the clutch cover/engine case swapped to one without the kickstarter hole in it, like the 750's.

rstnick wrote:

I recall a discussion on putting a 6 speed tranny (is this what the GPz750 has?) into a 650. The kickstarter and gearing needs to be removed, and the clutch cover/engine case swapped to one without the kickstarter hole in it, like the 750's.

GPz750 is a five speed, the six speed comes from the 550's.

I think the 81 KZ650 has pretty much the same cases as the 750, as in no kickstart.

And a HyVo cam chain vs the roller cam chain of the earlier 650's.