You are running muffler pressure ain't ya? If your not running muffler pressure then what these fine gentle men are telling you would be wrong. (I can't even imagine any one not running some sort of pressure on a glow engine) Do these engines have the remote needle valve assemblies that are on the back plate. If so it does take a bit of turning over with an electric starter and the muffler outlet blocked off to get fuel to the spray bar.