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setting points 1985 4.5hp

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buddyo

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I have a 4,5 horse 1986 mecury ob I have to adjust the points. I move them by mistake , when replaceing the wire harness. How will I go about adjusting them? bud.
 
Re: setting points

I will see how badly I can explain this :)

With the flywheel off, remove the sparkplug as well (makes turning the crank easier).

Rotate the crank by hand (use a wrench but be careful not to chew up the taper where the flywheel goes) and observe the crank cam that causes the points to open/close. Find the spot where that cam pushes the points together (their closest point) and then use a feeler to measure that gap.

You are looking for a gap of .020". If it's "wrong" adjust the stationary part of the points (the part that's fastened, by fiddling with the fastener) until the point contacts "just" grab hold of your feeler.

That's about it....
 
Re: setting points

galamb said:
I will see how badly I can explain this :)

With the flywheel off, remove the sparkplug as well (makes turning the crank easier).

Rotate the crank by hand (use a wrench but be careful not to chew up the taper where the flywheel goes) and observe the crank cam that causes the points to open/close. Find the spot where that cam pushes the points together (their closest point) and then use a feeler to measure that gap.

You are looking for a gap of .020". If it's "wrong" adjust the stationary part of the points (the part that's fastened, by fiddling with the fastener) until the point contacts "just" grab hold of your feeler.

That's about it....
Click to expand...

I think you are off on this one. Keep in mind that the points are spring loaded. Look at them while the points are on a low part of the cam. The points are closed and charging the capacitor (condenser). As the cam turns the points open and the capacitor fires causing the spark plug to spark. The cam continues to turn until it reaches a point where the points are open as wide as they are going to get. This is where you set the point gap. FYI, as the cam turns, the points close again starting the cycle over. That time between the points opening and closing again is your dwell measured in degrees.
 
Re: setting points

You are quite right - I am confused a bit :) (that's why I left the points/condensers work to my Dad).

I get criss-crossed between the Phelon ignitions (like this) that fire when the points "open" and the Phasemaker which fire with the points closed - I think I'll stick to the T3 and 4 ignitions...
 
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