This is actually a much longer story, but I'll make it as short as possible. I ended up needing to replace the rectifier in my 74 merc 500 50hp. Put in a new set of plugs at the same time. I started it in the test tank at the house and the thing ran like a dream. Started with maybe two seconds of cranking and ran smooth and quiet. I got it to the lake half an hour later, and no spark. Here's my question: The guy at the marine shop told me they don't make the old style rectifier any more. The old one secured to the engine frame with a stud on top of it that provided a ground, according to the schematic. The new style secures with screws that I had no holes for, so I zip tied the thing to the frame. Ran fine at the house, and no spark at the lake. Would the new rectifier being run without a proper ground cause it to fry again? Thanks!
