I had a Cub with an A-65-8 with no impulse mags. A kick back was not uncommon when the engine was just warm. Cold no problem with 3-4 shots of primer, hot no problem after 4 blades with the throttle in the start position. Warm, nightmare. I was eventually told that one mag should probably be retarded slightly. This is the one with the greater rev drop when the mag check is done. Starting on this mag only should reduce the possibility of prop kickback and truncated fingers. It worked for me
