sounds like the needle is dirty in the carb. you need to take apart the carb, remove the float and needle. blow through it.
Could be just varnish making it stick. Easiest thing would be to shut of gas, remove hose from carb. Take screw out of botom of carb holding the cup in place allow gas to drain out. Then squirt carb cleaner from auto stores into the hose going to the carb use lots let it soak overnight, drain again, turn gas on and try it.
Selinoid on bottom is a shut off, conected to safeties .
Kilo, September 2005