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Help with stator points on 1970s mercury 4.5 hp model 45

T

Trevor.

New member
I’m having an issue with the points on my 1970 Mercury 4.5 hp Model 45 outboard. When I rotate the cam, the points are open about 60% of the time and only closed the remaining 40%, which doesn’t seem right. I set the gap to .5mm at top dead center, and it stays almost the same throughout the 60% of the cycle. It does close right after top dead center but opens up again and stays open when the piston is around the bottom of its cycle. Anything helps, thank you.
 
“…while the quickly collapsing magnetic field in the spark coil …”
That’s a real blast from the past!
Over 4 decades ago, when I was in flight college, the military wonks running our training would send us two half days/week over to the aircraft maintenance school, to learn all about engines & all the modern, (and sometimes not so modern), systems,
I distinctly remember one portion on magnetos, & only because it was stressed it would be a very important exam question.
When queried about how the spark was finally generated we were instructed the only correct answer was- “ by Lenz Law, the magnetic field collapses…”
To this day I’ve never understood why it was important that we were never told what process in physics Mr. Lenz had discovered, only that we could recite his name, (spelled correctly), when queried about how a magneto worked.
 
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