MTFCA Forum

I have an original KW 1913 coilbox, that is misbehaving. I can't see any visual evidence that there is a carbon trail, but that is what it seems. I'm not much of an electrical minded person, so am interested in hearing true answers, and no speculation. I didn't think it was possible to get a carbon trail in a solid piece of wood, but can you?

Yes, wood is basically carbon waiting to burn. That said, to get a carbon trail in your coil box would require a dire problem in the plug/wire or more likely water in the box. You didn’t wash the original dirt off, did you Larry?

Andy

Most carbon tracking occurs on the surface of insulators, but it can occur internally, especially in wood. If you want to keep using original wooden insulation parts, you might take the device apart and look very carfully all over the surfaces of wood parts, paying close attention to the end grain, for any evidence of carbon tracking or a split, gouge, or void of any kind. Look carefully around and into screw and bolt holes for any sign of deterioration. Rust stains might allow electrical leakage. Clean up any visible damage,rust, etc, then get the wood absolutely clean and dry and soak it in thinned down shellac or clear polyurethane to seal it. Let it dry completely, then re-assemble. Also be sure that any porcelain insulators are free of rust stains and cracks. Pencil marks on wood can conduct high voltage.

Larry-
I think so.
I have a 1913 coil box that I had on my 1911 for a while, but it would have a slight miss. If I took it off and bolted on an ugly steel coil box, it would work fine. I double checked the switch and all the wiring, but could never find the source. I can't see any carbon tracking, but it is what I suspect. With a wood coil box, I'm afraid carbon tracking is a death sentence.
-Keith

The carbon track can exist within the wood panel and not necessarily on the surface of the wood, where it can be seen. Especially true with plywood, which I realize is not the issue here.

Larry, These are pictures of an original KW coil box you posted in 2019. Not sure if this is the one you referring to. The box looks good but the wires look questionable. Have you inspected them recently or replaced them?

Hi Larry,
This may not be a good way to check this out. If it's not someone chime in please! Working on a friends 17 that would not start I checked the
spark first as that seems to be were you start. I took the plugs out and hand cranked it till a coil buzzed, I had no plug sparking so I picked up
( very carefully) to see if there was spark to the plug. There was so I went to the next. Same result but I noticed that when I picked up the plug
when I got it to a to large of gap for the arc to cross I could still hear it sparking. I turned out the lights and I could see the spark lighting up the
inside of the coil box. Finding out that I had 4 working coils I cleaned the plugs and had good spark on all. Turns out the engine had 3 stuck
valves and once the valves were freed up it started and ran fine. I didn't think anymore about it untill you posted the question. This may be
a way to find a carbon trail or could be a way to make one or how one gets started when something happens to open the circiut? I know water
will but don't think you would get your box wet.
Craig.