MTFCA Forum

Yeah, I know. The easiest would be just to throw in a renewed coil ring and be happy, but why spend hundreds of dollars if it ain't broke?

I have my engine out and partly apart to fix an issue with the clutch. The top terminal of the coilring was broke and now when that is fixed - how do I verify that there is no shorts to ground?

My plan is to set 6 or 12 volt to the terminal and ground and then test every coil with a piece of sheet steel to see if it gets attrackted to every one of the 16 coils. I may also use a compas. If the coils suddenly stops working there is a short to ground. If non of them works, there is a broken connection somewhere.

Does that makes sense?

And we do have a guy here in Denmark that do new fiberblocks for the top terminal and rebuild coilrings

Since the forum was down I posted the same text on Facebook)

Ha! OK - I'll go and read the f***** manual!

You not only need magnetisme on each coil but the magnetisme also need to change N-S between each coil.
To control this make a loop with a 12V 21W light bulb, your magneto coil ring and a 12V battery. Use a compass to check the magnetisme and the change N-S.

Good luck
Andre
Belgium

last photo.

The field coil may be working, but if it's an original piece, that doesn't mean it's a good idea to re-use it. The cotton wrapping has become brittle and can flake loose, sending pieces into your oil line to clog it. Further, the windings have a considerable amount of metallic dust that will tend to short the bobbins between the turns, reducing the output. In addition, it has soaked up other dirt that you don't want in your engine, especially if it's been rebuilt. You wouldn't re-use the old, filthy oil you drained out of your engine before rebuilding it, but the effect is much the same, with the addition of the loose bits of wrapping.

Terry Horlick once posted photos of the results of an original unit that had one of the windings vibrate loose in useage, and you sure don't want to create that mess in your engine and transmission.

Really, the $250 or so spent on a new field coil is cheap insurance.

RV

I'll bet a field coil from here to Denmark would end up being more than $250 (though I do agree with you and always hate to see an old coil go back into an engine, considering the trouble to replace due to premature failure).

Yes your compass idea should work well. I have done the same thing. After soaking my old coil in acetone and brake cleaner I used gasket shellac to seal it up again. In theory you could use that penetrative wood preservative used on soft boat hulls, but the guy who rebuilds the coil in the future might not appreciate that.

As R.V. said, you shouldn't reuse an old coil ring.
Buying a rebuild one in the USA will go over $300.- part plus getting it in Europe. ( the raison why I started to build them my self)

From Belgium to Denmark it will be better.
I can build you one but it will take some time. I need to build four before it will be yours. Just send me a pm.

Andre
Belgium

Scott, you're right, but actually I had Andre in mind as he is in Europe and not far from Denmark. Shipping on a field coil from the US would run more than $100.

RV - that would certainly be my option if it was me

I Always tested the coilring before I put the Engine together .
Toon