Converting the Onan to Dual Fuel

I made no modifications to the carburetor. Propane is injected into the side of the aluminum air cleaner adapter. I drilled and tapped a 1/8" NPT hole in the side of the adapter. Then installed a 1/8" NPT to 3/8" hose barb. The other end of the 3/8" gas line is connected to a hose barb on the 3/8" ball valve at the zero governor. I fabricated a new air cleaner adapter from a copper pipe cap. The 1/2" hole in the center (along with the air cleaner) provides enough suction to draw the propane up from the zero-governor. Do not forget to re-adjust the main jet on the carb if you plan on running on gasoline. The restriction from the 1/2" hole will make the carb run slightly rich. So the main jet screw must be turned in slightly. The copper pipe at the top of the picture has nothing to do with the propane conversion. This is a home-made replacement for the crank case ventilation hose that was rotted out.