Z50 Head on CT70?


New Member
I have a CT70 motor with damage on the cylinder head. I also have a Z50 clone head cylinder left over from another project. Can any tell me if the z50 head can replace my damaged ct70 head?


Well-Known Member
The short answer is no, or at least, I would not do it. Both valves on the Z50 head are a little smaller in diameter, and the carb manifold opening has a smaller ID as well. Would ask around here or source a rebuildable CT70 head on e-bay. However, I would look closely at the pics and ask questions about the condition of the valve seats. You may be in for s few more $$ in expense if the seats are pitted and need cutting.

I've seen a few aftermarket heads, "E22" casting comes to mind, that are compete and cheap. Have no experience with this head. But if they are like most things in life, you get what you pay for.


Well-Known Member
The tiny intake port of a Z50 head will strangle a 72cc motor. And, you would need a smaller ID intake manifold to match. Neither the carb or intake can be larger than the port, if you want it to run right. By the time you've replaced the intake, carb & airfilter you may have spent more than was needed to source another head, or repair the existing one.

What kind of damage has this head sustained?