Got the replacement set of points (Sierra this time instead of OMC/BRP) and that fixed the problem. Comparison of their geometry---old points, to new OMC, to new Sierra---proved that the angle of the arms on the OMC points was indeed the problem. Mysterious how I could have received two sets...
There is indeed a difference between old and new rub surfaces--the new is bigger by about 10 thousandths, which would tend to make the points gap more rather than less, so obviously doesn't get to the problem. (Maybe that difference is due to wear?) Now I've carefully compared the geometry of...
Thanks to everybody. I've been noticing more and more aftermarket parts problems lately--low supply and low quality. It's getting harder to keep my old stuff running--tractor, car, mower, and now boat.
I did as you said--removed the points and backed the cam screw out a turn. Same result. No gap. For what it's worth, the cam screw looks to be well positioned. Looking at it, I can't see what could be wrong except that the points aren't the right part. Comparing the old to the new (see pic)...
Had no spark in either cylinder. Tried everything I could think of and finally decided to rebuild the ignition system. The pic shows the bottom cylinder points. No gap at peak adjustment. FYI, I'm pretty green at this...
Just installed new points, coils, condensers, and wires and found that at the cam's top position and with the points adjustment screw at maximum gap, I have virtually no gap. Both sides have the same problem. The points were purchased from Marine Engine (part #580148) and are correct according...
