1980 KZ750E Engine Replacement

Hi

Looking at some ideas on engine rebuild or engine replacement and was thinking about what engines might fit a stock 1980 KZ750E frame? Since, parts are hard to find and can get costly for just old worn out engines. What engines might fit this frame without any or very little frame modification?

Do I go with the stock KZ750 4 cyl. or can I use the 750 twin? Would a say 1990 ninja 750 or 600 engine work?

Does anybody have any advise? Do you have any engines that would work for sale?

Thank You
Ray

Hello Ray...if you want a drop-in motor that fairly well bolts to the same frame, you should be considering 750(4) motors from 1980-1983 (although the early ZX750 [1983-1985] motors might also fit). A similar motor is also the ZR750 (1992-1993) and one of those might be adaptable. Note that these motors are all air-cooled. If you are particularly handy, you can get almost any motor to mount, but most will require a fair amount of modification. Later bikes are water-cooled which adds an additional layer of confusion when swapping motors.