is this too hot

[john.nash]

It's got to the stage when I could be thinking electrics ...

I finally got around to the magneto. All the best intentions months ago came to nowt.
By cleaning the various bits, I can get at it, it sparks very, very well by just flicking the armature around (with your fingers).

As was advised, I slung it in the oven for an hour.
It's a fan assisted (i.e. very hot) jobbie and the lowest setting is 80 degrees.

After an hour, I had a VERY hot magneto that didn't spark at all.
Within 5 minutes, out of the oven, when it's still too hot to touch it's sparking as well as it was cold.

The question I don't know the answer to is whether even a good mag will not spark when VERY hot ....

[robin.parker]

John, I wouldn't do that again if I were you, whether the windings are shellac insulated or if a more modern material has been used, "cooking" is a bit drastic, now if you had a Rayburn with a gentle warming bottom oven, that might be safer. As it is I reckon you have a pretty good mag!

[Steven.Carter]

I checked my Mag in the microwave oven, you should have seen the sparks

[nevhunter]

The LAST time (and it will be), that I heated an armature, a lot of the shellac or whatever is there came out of it and the windings went soft. That was the end for that coil. When they are being manufactured they are subject to vaccuum just like when you are gassing an airconditioning unit. Very moderate warming and a vaccuum will do the job of removing moisture, but most of the time, you are wasting YOUR time playing with "OLD" coils. The fine copper wires corrode and the insulation breaks down. The result is that the coil runs hot in service due to leakage and fails in a short period of use. A good spark is no indication of reliability. Nev