Reply To: 1948 Zephyr, points

[aquasonic]

There is another possibility that comes to mind why you can turn the crankshaft without the points opening and closing. If the points pushrods exist, and are not touching the crankshaft cam when it is turned, then maybe someone loosened the points set screws. I have motors with similar style points such as the Johnson TD-20 model, from the same time period. The points have to be pushed into position, then locked in with the set screw. If the screw is loose, the points tend to slide away from the crankshaft, as they are under spring tension from the round end of the pushrod pushing against the springy point plate.

The flywheel does not open the points, the crankshaft cam does. That is the whole purpose for the points pushrods. The crankshaft turns with the pushrod riding it, or near it, (if adjusted properly). Once it hits the “high spot” on the cam, the pushrod pushes the point plate and the points then open.

With the set screws loosened, try turning the crankshaft to the point where the “high spot” matches up with one of the pushrods, then push the points toward the crankshaft until they open slightly. Once that gap is 0.020″, then tighten the points set screw. This may take a few attempts. All points need to be clean, and adjusted properly, and there are several variables that affect the adjustment, such as contact wear, pushrod wear, etc.

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