It seems worthwhile checking the adjustment of the speed control lever, to make sure it really is applying full choke. If it needs full choke to run, there is something horribly wrong with the carburetor, and it will be necessary to go through the full process of checking it to find and fix that. On the other hand, if the speed control is slightly out of adjustment, it may only be necessary to go through the speed control adjustment procedure. It may be that any speed control position but "full choke" is actually operating the kill switch.
Once long, long ago I called a TV repairman because the TV suddenly had no picture at all. The repairman asked if I had recently had a visit from a small child. I said yes, immediately before the TV stopped working. Repairman smiled, walked up to the TV, and adjusted the brightness, which was down at zero. Perfect picture returned instantly. The repairman says he got a lot of those, and they were very good for his income.
