RE: Reed valve on RCGF 20cc engine
The reed faces to the inside of the crank case. You want the screw on the opposite side of the openning to the crank case. If the screw is on the same side as the crank case openning it might run, just not very efficiently. FYI- If you need to replace the reed, the one from the rcgf 15cc works. I've done it.
Edwin