How can I determine engine power?

[DanSpd]

Basically how can I determine if engine is 30.5cc and not some old 23cc?


On my engine I can find "chung yang" and serial number only.

 

[Obeast44]

I don't know if CYs come with any castings on the side that tell piston size. A 30.5CC motor will have a 30mm stroke and a 36mm bore. If you have a micrometer you can get those measurements fairly easy.

 

[Martin_]

At the cylinder base you should see... 28 36 ... this is the stroke and bore.


As for the 30mm stroker crank, you have to measure it yourself since a 30.5cc is not a factory engine.

 

[hamster huey]

Yes. The factory bore and stroke is stamped into the head. They will say 28, 32 or 28, 34 or 28,36. I think they all say 28 because they are all stock 28 stroke. Ive never seen or heard of a CY with a 29 or 30 stroke. The side of the head that is stamped is hidden under the coil if I remember right so some dissassembly is required to find it.

 

[Martin_]

There is CY head stamped 30 35, this is the CY billet head 29cc motor.

 

[Deluge1]

The numbers for bore/stroke are on the clutch side of the head. This could also help.


Calc. Displacement