Premature point wear?

[Alan]

Very much appreciate the info!
I could not adjust the points to get them to break at the right time. Ran out of travel on the adjusting screw.
I have both new points and eccentric adjusting screws on the way.
I’ll report back if I learn anything.
Thanks again;
Alan

[fleetwin]

Funny, but it almost looks like someone has had needle nose on those breaker arms. I have reused points with more rubbing block wear than seen in your picture…Did you try swapping points from one side of the mag plate to the other? This is a very interesting condition, one I have never experienced, but seems to have been reported here a few times in the last year…

[Alan]

Thanks to all!
Fleetwin, I did not swap sides with the points. That would have been good science. But as soon as I saw that it was impossible to adjust one side fully, and that the other points were also out of adjustment, I pulled them immediately.
What I thought I was getting was two sets of OMC points. I got them from a member who sells NOS OMC parts, which have always seemed to be of top quality. So, these could be, “aftermarket”, or cheap knock-offs, or something, but I did not get them for cheap offa feeBay.
If anyone put any part of my points in any kind of pliers, I’d get bent. They do look a bit chewed, but I have no idea why. Did I not put enough lube on the cam and new oiler wick I installed? May be.
Also appreciate learning about 2 stroke ignition, and glad to know dwell is not very relevant. My one mission was to get these to break at the clearly indicated times. Which I have done successfully in the past. In fact, I got good enough to set them to break at the middle of the mark. This time, no amount of adjustment would get me there.
Feels like these were defective to me. I look forward to a side by side comparison with the new ones.
I very much appreciate the support!
Alan

[fleetwin]

OK, so you are working on a V4 with distributor….Is it battery powered ignition, or magneto distributor. The 12 volt distributor cap faces upwards, the magneto distributor faces down toward the propeller. Is the distributor shaft worn, does it have slop from side to side?

[Alan]

Excellent ideas; hadn’t thought about slop in the distributor. But no, it seems to have no play at all.
Yep, big ol’ V-4, with battery / distributor ignition. All new ignition parts, including spark wires. I learned, (the hard way) to twist them while testing; they tested fine until I moved them around, and they then revealed themselves to be very tired and broken.
I also verified the points cam is right side up, and the cam did have a thin layer of lube.
Appreciated!

[Alan]

I think the answer will be worn pivot bushings. DK the real name, but the bushings are thinner on one side than the other.
I did not lube the post the points ride on, but I will next time. But I can feel slop in them when mounted.
I’ll post a new thread when installed.
Many thanks;
Alan

[fleetwin]

Cool, I never considered this issue! Worn breaker arm bushings would certainly result in “lost motion” and inability to set the gap properly…

[Author]

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