Ahh its always something, this morning the wind on the North Shore is howling, there are whitecaps in the harbor behind where I live...no boating today!
Why do you think that plug loosened up? How are the threads on the plug?
The dist gear issue, that worked out OK?
PS I finally solve a low voltage issue to my dash wiring and ignition system...that's been dogging me for a few years...I thought my voltmeter was just old and reading low....because I had 14.3 V at the batteries with the engine running....well...pulling out the ign switch to test....that old voltmeter was 100% right! I had battery volts at the Batt terminal, but 10-11 V at the ignition terminal with the key on..... I went through the dash harness, every connection could find nothing corroded or loose....there may be a few connections behind the engine that I have to check....
I solved it temporarily by running an additional 10 gauge wire to feed the fuse box, from the battery switch common terminal, fused at the common terminal.... now I get battery volts at the volt meter...before I was getting like 10-11 V with the engine off, ignition switch on. Engine on, I get 14.3V on the gauge just like at the batteries.....
And, the engine starts and runs better, smoother...etc....a good thing to check on old boats if you run into an operational issue...that normal fixes don't work for.....my ignition system was likely getting starved for voltage because I didn't believe the dash gauge....