Propane = less BTU's = lower power = not a good thing for racing or wanting to go fast.
Denny
No, you just use more is all.
In fact, propane is a superior fuel. By most standards.
104-112 octane. You've gotta get into racing gas to come close, and propane is $3/gal. High compression ratios and timing advance? Yes please.
Gaseous. No atomization or turbulence required for good fuel mixing. Port that intake like crazy
Pressurized. No need for pumps to get it where it needs to go
Clean... Practically zero engine deposits, and much less stinky exhaust
Unlimited shelf life. Park your go kart in the fall, the fuel is just as good as they day you stored it. No varnish, no corrosion, no "old gas"