Differences in valves for each generation of the Predator 212

There are 3 different types of valves in the Predator 212cc engines:

The 1st generation Predator 212cc is a non-hemi engine with a 25mm intake valve, and a 24mm exhaust valve. These valves have 5.5mm stems, which is common to the GX200 and 196cc Clone engines

The 2nd generation Predator 212cc is the hemi engine with a 27mm intake valve and a 25mm exhaust valve. These valves have 5.5mm stems

The 3rd generation Predator 212cc is a non-hemi engine with 25mm intake valve, 24mm exhaust valve. These valves have 5mm stems. The aftermarket does not support this size stem.