My 1979 nc-50 is havin a bit of trouble. Before winter it fired right up first time. Now, it won't start unless i pour gas directly into the cylinder. I took the fuel line off and its not the petcock cause gas is flowing freely when i opened it up. When i started it by just putting alittle gas directly into the cylinder it would go for like 5 seconds and then die, like no gas was making it from the tank into the cylinder. I'm thinking its the carb, but just the fact that it ran so good before winter wants to make me believe that the carb was pretty clean. Any suggestions would be great.