Is the stator plate reasonably tight on it’s mount? Is there excessive side play in the crank? Is the cam loose on the crank, or cracked? I’ve seen several of these ignitions where the primary coil lead has rubbed on the flywheel hub, grounding things out, sometime intermittently, but I don’t see the leads exposed here. Likewise, if the ground leads are worn completely through there will be problems. Condensers can check out OK with a VOM but still be leaky. You might want to swap them out. It’s not too common, but possible, for someone to have used an arm puller on the flywheel and pulled it out of shape. Many people would probably agree that the quality of old-style ignition parts has been deteriorating, and that probably includes new OMC "OEM" parts.
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