A word to the wise- if the inlet port of the carb/mixer was loaded with enough "tar" to restrict fuel flow, than I would suggest either rebuilding/replacing the fuel regulator. That's where the tar residue was formed.

Also- make sure the fuel you are using is grade 'HD-5"- this is the fuel type reccomended for internal combustion engines- propane is not all the same. Don't be surprised if your propane vendor tells you different- many don't know what they're selling.