Try taking the carb off (2 bolts) completely remove it from saw.There are 2 fuel lines to it the top one goes to the fuel tank.Try blowing it out with air hose. (EMPTY GAS FIRST LEAVE CAP OFF) before you do this !! Dribble a very small amout of fuel into carb hole .If saw starts and runs for a couple of seconds you need a new carb boot.Mowers4 you on Ebay about $10.You will have to disasemble saw to replace it.Take your time use cups for all bolts marking each cup.It's not rocket science and takes very few tools.Just had the same problem now my saw runs like new.
Frank
December 2006