Well,my engine is close but a litle larger.It has the stock zama carb,i just havent changed it yet.Its the 24cc echo.In the pic without the prop but with the rcexcl ign,without battery weighs 47-48 OZS.Set at 28 deg BTDC spins the prop in the pic at 72-7400 rpms.If you havent checked out the thread {dont gorget echo},go check it out.
Ive also enclosed a pic of my 21cc im working on.The one with the chevy orange cylinder.
A 21-22cc should spin a 15x8APC at the same RPMS as my 24cc.