Lazer,

for information only

The pump and pressure controller as built for the Orion left side.
The pump is driven by the crankcase pressure of the Enya 60 4C, but the combined regulator is like cline.
This combination you can compare with a Walbro carburetor.
The amount of connections show us this is more complicated than a Perry pump (right side).
There is a sixth input on the backside to sense the airpressure in front of the carburetor input.
It is this picture that shows us also you need a lot of R & D to make a reliable and accurate fuel system for a 4 cycle I think.

Cees