I had 4 Super 1050's, one my Dad bought new in 72-73, it had a Tilly, the other 3 had SDC's. As stated no decomp. I started running the 1050 as my daily use saw when I was about 16-17. I found out quick if you want to keep your fingers when that thing pops back, keep the throttle cracked at least half way, or use the throttle lock. When I first started running them a was just a tad afraid of them, and tried to start them "easy". Ain't no easy about it. I learned to find a log, set the tip of the bar on the log, hold the throttle open with my right hand, and crank with the left. They never popped back. If you try to pull it over with the throttle closed it will pop back and rip your fingers off. I asked one time why it did that? Answer I got was, "reed valves", all saws with reed valves do that.