I watched this video from Project Farm guy last night.
He has also done them on gasoline vapors. Hook up for this is the same as for wood gas. For a stationary application like a generator it would be easy to just feed lines from both the gasifier and the vapor container into a Y with shut offs from each before the Y. It you normally start the engine on gasoline to start sucking in wood gas then you could start on vapor, open the wood gas valve and shut the vapor valve without having to time the gas running out and starting the wood gas feed. Running on vapor the carb is just a port with a throttle and choke. Not much to screw up.