Did you store it with fuel in the tank? I did that once and was not good, i got the tank clean but had to replace the fuel line because it was all gummed up. also check for some air leaks, make sure the glow plug is good. a good way to ckeck for an air leak that works for me is to pull the fuel line from the exhaust and blow into it, i also use for priming
, the fuel should go to the carb like a rocket, if it gets there kinda slow check further into air leaks.