Needle in the carb probably not sealing off gas alowing it to seep, first I would make sure all the carb screws are tight and the two screws that hold the carb on are tight.

If you are running 10% alky and it got a few years on it it probably time for a carb kit which will include a new needle valve gaskets and spring. If you go that route just make sure you get the numbers off the carb. body to take with you. it's probably a Zama carb

rcmoser assumes you are familiar with carbs. If you have an adjustable carb there will 2 or 3 screws you will not want to touch for this. They are the adjustments screws for your carb and control the fuel air ratio your engine receives. You don't want to mess with those yet.

Check the spark arrester screen at the outlet of the muffler. Clean that screen by holding it with a pair of needle nose pliers and then hit it with the tip of the flame from a butane lighter. Get it good and hot and the carbon will turn to ash. Once the screen is clean try it again. If the engine is still hesitating, pull the muffler (two bolts) and make sure the exhaust port is not filled with carbon. Because a two stroke engine has no valves, some of the fresh air/fuel charge escapes the combustion chamber before it is burned. Because of the hot cylinder and port, this unburned fuel mix carbon's up the port.

After you have checked the screen and the exhaust port if the engine is still hesitating, open the main or low side carb jet 1/4 of a turn counterclockwise to richen the mixture. The main jet on a diaphragm carb is always closest to the cylinder. The other jet is for the high circuit which is wide open throttle.

In a piston ported engine the piston skirt is what seals the incoming air/fuel charge into the crankcase. As the engine wears, the skirt begins to thin and this will allow the fuel vapors which are in the crankcase to be pushed back out through the intake.