Will it fit?

Hello all and thanks in advance for the help,

I have a 1981 Kz750 that is still pretty much stock. I am having issues with the clutch and in the process of finding parts came on this full trans from a 650 that I think is from around the same year model. The only difference I can see is that the 650 trans has a kick start and electric start while my 750 only has the electric start. They appear to be the same size and bolt pattern and look like they would be interchangable. Truthfully I wouldn't mind having a kick start but I was wondering if the gearing would be the same and if anyone knew of any problems that would arrise from having a 650 trans hooked up to a 750 engine? Also if the whole trans can't be switched would the clutch parts still be interchangable?

I believe the transmission does not "hook" to the engine like in a car, but the trans is built into the engine (it's inside the cases that hold the entire internal engine parts). So, I think it is not possible to use a 650 transmission with a 750 engine.

Do you mean trying to use the 650 gears/shafts inside the 750 engine?

the kz650 and the 4 cylinder 750's use exactly the same transmissions.

If you wanted to add a kick start you would be better off starting with a bottom end that had it. The cases have a hole drilled in them for the kick start shaft to pass through.

If you were determined enough to start drilling holes in your cases, and assuming the other mounting tabs for the kick starter were cast into your cases... then I guess you could with some effort fit the kicker. But if it were me, I would just use another bottom end, one that came with a kicker.

I have the opposite problem; I am in the process of removing my kick starter and I am not quite sure how I plan to plug the hole there on my cases. I would snap a picture for you but my cases are all covered in masking tape (ready for bead blasting). In the end I may just take my own advice and use a case that was never had a kicker (therefor no hole to plug).


Good luck!

So, you two should swap!

kztee wrote:

So, you two should swap!

lol not a bad idea... hell I would even bead blast the case for him (as I already spent 3 hours covering it in masking tape! )

but I am going to be picking up a 750 motor in a week or so that I got off ebay for $25 and I doubt he is located in Northern Maine!

One of the members here reborn650 put 750 cylinders ,,,,, actually 750 bored out to 810 cylinders ,,,,,on his 650 transmission. It did take a bit of work to make the fit but it can be done that way. Would it just be easier to fix the original clutch.........hmmmm.