This would be cool. Convert a 4 stroker to propane. In researching it, there are no great advantages other then cleaner burning fuel and being more "green" It would in fact cost more to build. I have not yet found any thing on engine longevity. Also I am only finding kits with a screw type throttle for generators, not some thing like a motorized bicycle where it would need to be adjusted manually. Dunno, would just be a cool build.
The Emergency Preparedness Tip o'da Week.