Chris- A connection must be made from the heater exhaust to the intake manifold as fuel is pulled in by the engine’s vacuum and is not pumped in. Generally the fuel is taken from the carb’s float bowl using a siphon that is supplied with the heater or any still reservoir of gasoline can be used such as a shallow metal can that can be refilled with a funnel. The heater only works when the engine is running. Look through the website and all is explained. I’ve brought over to the U.K. several heaters when I’ve gone to John Gillard’s. Can’t recall exactly who they were, though.