I have a FT-120 Gemini II engine that I bought used. I don't have any history of the engine. The crankcase says "FT-120 II" and it has the carb choke. These lead me to belive it is a Gemini II engine and not the Gemini. The serial number is 0728. I was looking at the exploded view of the Gemini II engine on the OS Engine website and it shows the engine cylinder head and the rocker support to be these.



My engine has these.



I was going to replace one of the rocker supports, but can't find the ones that would fit my engine. Did OS change the cylinder head assembly some time during the production of this engine or did some previous owner swap out the original heads with the ones I now have.
Thanks for the help and I hope the pictures come through.
Paul

According to the diagrams we have, the info you've received is correct. We can't speculate about why your engine has the different kind of rocker arm supports. That type is not available any longer from O.S. They were discontinued over a decade ago.

Do you know what engine the head and rocker that I have were intended for?
Paul

We can't tell by just looking at the parts, bu they look like parts for the older FT-120.