Hey all, I pulled my starter off this morning (remembering to remove the Bendix first) but when I look into the hogshead I can see the insulating wrap has been pulled from one end of the visible magneto coil. I guess the last guy wasn't as careful as I was. How much trouble does this spell for me?
I mean it's one coil of what, a dozen? If there's still electrical continuity should there still be enough mag coils left (probably) intact to power the ignition?
If your mag was working before you pulled the starter, and you didn't damage it, it will probably work the same as it did before. If your work did the damage, then it is a guess until you get the starter back on. The individual conductors are insulated are insulated between turns as well as the entire coil wrapped before it is installed on the ring. If you have a short in the coil, it will decrease the output, and a ground would decrease it more.
Unfortunately the car wasn't running when I got it so I have no baseline at all. It doesn't look awful, just that the insulating wrap is peeled off the copper strip coil directly adjacent to the starter shaft. The coil itself looks more or less okay, just a bit of a ding in it where somebody wanged it with the Bendix.
If it were mine, I would put the starter back on and get the engine running. The mag might work, or it might not. Then next time you need to pull the engine for repair, you can replace the mag coils. It is a good idea to do so anyway, because the original insulation is usually very brittle. The coils will run on battery, the car will not be quite as fast as on mag, but it will run and not a problem on battery.
I am with Norman K on this one. There are sixteen coils in the field-coil. Any one shorted to ground may kill it. But two or maybe even three turns of one coil shorted to each other may not hurt it much (a small loss of both current and voltage). Actually, all that varies some on the specifics of exactly where the short is.
A small effort to try it. And it may work fine for many years. But keep the battery well charged just in case (to finish the tour or get home on).Many Ts have been driven for many years and thousands of miles on battery and coils alone.
Drive carefully, and enjoy, W2
Well, that's a relief that it *may* be okay. I'll just put everything back together when that stage comes and hope she works.
Agree. Put it back together and motor on, with or without magneto. A bunch of them have damaged coils adjacent to the starter drive and still work.
If there isn't loose wire ,nuts or etc in the engine pan it might be OK.
If the insulation is cracking off the mag ring at that point and the copper winding is intact AND if the engine will run on Mag it could last a good while.
Better yet you could get a small brush and with the starter out use the brush to clean the oil and grease of the exposed area.
Get you some type of varnish or insulation spray and coat it the best you can.
And yes I know its a 'farm fix' but it will work for a good while till you want to spend the time and money to fix it.