It sure sounds to me like your flywheel magnets are hitting on the coil laminates. In the pic, the screwdriver is pointed to the boss on the mag plate and to the edge of the coil laminates, or ”heels” as they are called. If the ends of the coil laminates are protruding past the edge of the boss, even a hair, they will stop the flywheel dead in it’s tracks. Check both coils carefully, and loosen the screws and align them evenly. Otherwise you can purchase the OMC special tool that makes this adjustment easily.
My suggestion is to purchase an OEM tune up kit for around 30 bucks or so, and replace both sets of points and both condensers and be done with it. Don’t waste time with Sierra points, they are junk. Set the points to .020 thousandths on the high side of the cam. The .020 feeler gauge should have a very slight drag while checking the gap and inserting it squarely, and carefully, at the same time. Once again there is a special timing pointer that is used with an ohm meter etc. to set the points, but using the feeler gauge method will work fine, if you do it correctly.
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