I have two Stihl saws, both older than yours (021) (039) and since they were brand new, they required 12 pulls fully choked before they would fire. Then I "half" choke it and it runs good. They'll start first pull all day long, after this initial hassle. Even the next day will only require two or three pulls for first start, but leave them set for a week and it's 12 pulls all over again. The dealer begs me to bring them up so he can "fix" them, but they run perfect when they finally start, and I can live with it.
So - like Dean sez - it may be flooded, or it may need the snot cranked out of it on full choke 'til it decides to fire.
You've already tried a new spark plug?