Moped Army

Here's the deal. I was not getting any fuel into the cylinder so I thought it was the carb. I finally decided to check the suction, so I took off the manifold and cranked the motor and no suction which would explain why no fuel was getting into the cylinder. I pull off the head and the gasket was in pieces and somebody had put like an RV clear sealer as a gasket. My questions are, could this affect the suction from the piston, where do I get another gasket, and what other possibilities could affect the piston not pulling fuel into the cylinder???