Their are two way to convert to propane. Only one way will work. Typically simple conversion is to deliver a propane gas vapors from the tank to the carb, this has shown NOT to work.
What works good is to get a tank set up that will deliver liquid propane to the carb.
This set up is a little more expensive but when just using the vapor of propane you WILL have a freezing carb problem.
The facts are propane is 10% less BTUs than gasoline. Some say they can tell the power lose. In reality you just use about 10% more propane compared the the same as gasoline. The power is not much of a factor from what I have seen.
On the positive side it is much cleaner running, and much cheaper that gasoline.