I have an older engine that came off an old sears chainsaw, it has a magneto but uses points to fire the sparkplug. My question is can I rig a coil with a battery pack to drive it and let the points tell it when to fire? This would allow me to do away with the flywheel and the mag portion of the ignition. Not sure of engine size, I measured the bore as best as I could and then the stroke and it came out to be 53cc.