carb -- ca125 too small. COuldnt lean it out. terrible mileage. On dyno it was dumping HCs. Bought ca225, range +- on idle. Used adaptor to fit ca225 to ca125 throttle body assy. suburban dealers have used parts they can't always sell. Joe: octane is simply carbon (?) bonds to be broken; propane has 3? 4? CRC book ... more on safety issues, ie. hnadling, accidents, etc (accidents)