RE: RCD 26 CC Gas Engine from Hobby King
Sounds like the HG 20cc has a piston port type of intake rather than reed valves...? (for fresh fuel intake) The piston port is simply a port in the cylinder that opens as the piston reached TDC and the carb is bolted to that port with a mating adaptor or block. Reed valves (DLE) are better in some ways because as the piston begins it's downward motion crankcase pressure will push the reeds shut and contain all of the crankcase pressure - with a piston port the charge can begin coming back out if the intake system and rpms are not perfectly in sync.
Ernie Misner