I have a 1955 Scott Atwater model 3355 7.5 hp that needed coils. I found that a Phelon FG 7049 chainsaw coil will work, you need to remove one layer of core laminate . The points on this motor don’t stay closed long (about 10 deg). I set the points at .015 and got a lot better spark. The engine idles slow and starts easy now. I got two coils for $31.