MTFCA Forum

This is a rerun of my magneto issue. Several months ago after 65 years, the magneto quit in my 26 T - switch to mag - engine dies. Problem was not with the switch or wiring. I verified there was no AC voltage at the mag post with an analog meter. After removing the mag post several times for cleaning/inspection (no issue found), suddenly I had mag voltage again. Mag worked for several months although the output was only about 15 volts.

Suddenly, no mag voltage again. Before removing the mag post, I disconnected the mag post wire and verified there is continuity through the post to ground (about 0.5 ohms) using my digital ohmmeter. Removed and cleaned mag post (found no issue). Still no mag voltage. I verified the outside oil line fitting is not shorting out the mag. Not sure where to go from here other than installing a new mag post. Any suggestions?

I suggest you abandon this post and resurrect the old one. You're going to simply get the same litany of things to do/check, which you've already done, but no one recalls what they were.

It would be nice to see all of the things you've checked already rather than go through another 2 week guessing game before getting down to the things you still HAVEN'T checked

BTW, your last post on your other thread was:

I measure the end play at less than one millimeter (0.040)

You have most likely found your problem.

the fix: https://www.modeltford.com/item/3030SHIM.aspx

Rather than test the mag post again have you bypassed the post and stuck the electrical probe down into the hole and actually touched it to the electrical contact button on the coil ring?

Guess your right, I probably will have to wade through the same comments.

I checked Lang’s and Snyder’s but their mag posts don’t accommodate an outside oil line. I think I might invest a few bucks and see if a new post fixes the problem.

In the mean time, I will check the mag output directly on the mag ring.

Jim

click the link.

with nearly .040 endfloat on the crank, the mag post is not your problem

I’ve got the shim to reduce the gap but haven’t had the energy to try it. Guess I’ll have to take some vitamins.

I checked Lang’s and Snyder’s but their mag posts don’t accommodate an outside oil line.

It's part of an outside oil line kit, not sold separately.

My opinion, end play is over rated. I had more than .040 on my 15 and still rated good with an ECCT. If magnets are strong it should be ok to run. 15 volts certainly is. Heck I just put an engine back together after doing a quickie overhaul and not all of the poles were exactly what the book said it was supposed to be. Some were somewhere close some were to far away. Shimming would not get them all where they needed to be. It’s putting out over 33 V at 1500 RPMs. I don’t think there’s any debate that there is some importance but i’m not sure it’s as critical as most of us think it is.

I’m sorry that’s my opinion and my experience. I’m sure I’ll get bashed for it. But that is my results. Believe it or not I could even get it to start on mag.

Brian