Franklin Valveless piping

Does anyone know how to work the gas intake on a 25 HP Franklin Valveless? Mine has similar piping to others pictured on the internet. There is a gas valve before the flyball governor, then the piping branches off to upper and lower valves, both of which seem to go into the cylinder. The lower valve is piped into a fitting that seems to have a needle valve in it. To compound matters, there seems to be a chamber under the cylinder in which there seems to be an air intake controlled by about a 3" wheel. If anybody has any experience in running these engines, your help would be greatly appreciated. My engine is in great shape, and should run, if only I know the secrets of its gas system. Thanks!