You could quite possibly use a non OEM coil but I hesitate to recommend one without having tested it myself or knowing any of the specs of either. Some of the things to consider are:
number of turns primary and secondary (at least the turns ratio)
resistance of primary and secondary (plus high tension leads)
inductance of primary (the condenser in the points is usually matched to this)
not any or all the factors above may matter, near enough may be good enough. If you have a coil pack lying around I would say try it out and see if you get spark. The OEM coil pack is charged from an exciter coil and not a 12v battery so I would probably at least try to make sure that any other unit I was considering was also run from an exciter coil as this could possibly have a large effect of the turns ration as generally the output from an exciter coil is higher than 12v. It might just give a bigger spark or it might burn out plugs or kill the coil pack in short time.
I love the idea of trying it out but I'm not sure I'd invest $50 to find out without at least being able to compare the specs. If I had one in the shed I'd definitely have a crack just to satisfy my curiosity, to hell with the consequences! The OEM unit is $80 on boats.net, so it's still more expensive but not double. Have you tried aN outboard wreckers?
I have seen a little old 1KW genset converted to use a coil pack off a car, it worked fine, so who knows?!?
Whatever you do, be sure to get back to us on here and let us know. I at least would love to know the outcome.
