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It produces a nice 1/2″ spark from the coil lead when the wire to the points is scratched. Point’s don’t appear to be making, by meter, and there is no spark from the coil while cranking. So I presume the points need attention. Need to pop flywheel next.
That “reverse cutoff spring,” 313743, $39. Is it something I should expect to have to replace? Is it important? Does this motor have some special tendency to start backwards?
Interesting discovery: The red-painted battery terminal was on the negative cable, and the black one on the positive. So likely this setup has been connected with reverse polarity. So I expect various burn’t out diodes and suchlike. Interesting that the amplifier survived.
Time to check the shifting again…..
OK, so it sparks at the coil when the lead from the points is tapped to ground, but not when cranking…So, it does seem like you will have to remove the flywheel, unless the ground lead coming from the ignition point plate is not making a good connection. Perhaps the leads are frayed/broken.
The points are probably just a little dirty, there are two sets which are gapped at .010". The anti reverse spring could be causing a problem if it is somehow stuck grounding out the circuit, doesn’t seem likely though. The anti reverse spring is probably in OK condition and does not need to be replaced, but it is a needed item and should be replaced if it is NG. I am assuming you have a decent OMC manual for this engine that will explain servicing procedures in great detail.
Yes, if those battery cables were crossed, even for a second or two, I am quite certain the alternator rectifier diodes are shot, the shift circuit diodes may have been damaged also. We will get back to this after the ignition is straightened out. Be sure to check the resistance of the alternator windings while the flywheel is off, it is unlikely that crossed cables damaged the windings though.
Great news, the gearcase shifts OK, I thought it would. Did you fill with OMC premium blend? Normally, I would recommend doing a water pump job, but not in this case. Again, I don’t want you digging into this thing any farther than absolutely necessary. Once the ignition is straightened out, you can search for a decent control box/wiring harness…