Re: 1940s OMC / Johnson breaker points question

[legendre]

quote Chris_P:

They don’t wear as quickly as you are imagining. The set you have are likely the originals from the 40s!

I’d always assumed that was the case, but I wouldn’t know how to tell a set of late 40’s Johnson/OMC points from a 1960s-1970s replacement set.

quote :

It hits fairly square as well, not on an angle so beveled wear is not an issue.

Now that I think about it, the design makes good sense. Each pass of the cam swipes cleanly from one edge of the (flat) pushrod to the other. The situation on the other end isn’t quite the same. The end that actuates the moving contact experiences a a partial swipe, with the upper edge taking the brunt of the wear as the points open.

Having a radius on that end makes sense, as it limits the wear to a small radial area near the center line of the pushrod.