Gasoline goes stale these days much faster than it used to. You've probably got a combination of some gum and varnish deposits in the carburetor clogging up some passages, and gas that's already lost most of its lightweight hydrocarbons to evaporation. I once encountered a tank of gas that got so bad I couldn't pour the stuff out on the ground and light it with a match, and the car had only sat idle for a month. When the owner tried to start his freshly-rebuilt engine, the gas simply wouldn't burn. A tank flush and a couple of gallons of fresh gas fixed it. It might be necessary to put a kit in the carb before you get back on the road, and pay particular attention to a good solvent soak and lots of high-pressure compressed air blown through all the drilled passages as you reassemble it.
Next time, try to run the tank bone-dry or close to it before parking the vehicle, and put a heavy dose of Sta-Bil or some other fuel stabilizer in to prevent the gas from getting gummy.
Jerry
