The Harley Hummer Club

I just bought a 1955 Hummer that hasn't run in about 30 years. I bought a new ignition coil for it but I'm not sure the correct way to hook the plug wire to the coil. Could someone help?

You solder the wire to the small tab on the side of the coil.

There a dot of what looks like solder on the side of the coil but my soldering gun wouldn't melt it. I will try again. Thanks

Taking advice from a Briggs & Stratton service manual, they caution to NOT, repeat NOT solder the spark plug wire to the tab on the HT connection of the ignition coil.

Their reasoning for this advice is soldering makes for a rigid connection, and engine vibration can cause this connection to then crack and fail. Their advice, I'm paraphrasing here, is to simply remove some insulation from the wire, run it through the little hole in the tab, then twist it around itself to make a mechanical connection, and then wrap or cover with insulating material as available.

I have seen several similar Bendix magneto coils fail due to soldered connections cracking off right where the tab comes out of the coil.

In the case of the magneto fitted to a '55 Hummer, when correctly installed, the HT lead connection is on the engine side of the coil and there is a soft cover that the spark plug wire fits through and covers this connection. its held in place by the coil and the alloy stator frame. Sorry, I don't have the P/N for this cover part.

As far as replacement coils go, a #399-125 coil for a Mercury outboard motor has the same dimensions and leads and is an effective substitute. Only difference is the LT leads come out of the coil at the opposite end so you need to either splice in extensions for these LT leads, or mount the coil with the HT tab on the side cover side, opposite the OEM Hummer arrangement.

Back in the day I had (still have) a 55 Hummer magneto grafted onto Maico engines that I used for enduro competition use. Reason for this is the lighting coil which provided reliable, if not too powerful direct lighting rather that the Maico DC generator and battery set up. Rode enduros for several years with this setup and it was totally reliable.

It is invaluable, first-hand information like the above, which allows us, and those after us, to enjoy this hobby, bring these bikes back to the street, and cause other folks to say, “I didn’t know Harley-Davidson made such a small motorcycle.”
Thanks for the question, the background behind an excellent answer, and for the personal ‘alternate use’.

There is a comment made in the movie HELLO DOLLY where the store owner explains, ‘Money is like fertilizer. It is best used when it is spread around.’
I would think knowledge falls into the same category.

I don't have a tab. All I have is a 3/16" round dot that looks like solder.

Grind the 3/16 dot of solder down almost flat with the coil body. You will then see a brass pin in the center. Apply a little solder to that pin, then solder your wire on. After it cools, put a bit of silicone over the solder and let it dry and youll be good to go. Benn there, done that

That worked but now I get spark on the first kick and nothing after that. Points look good. Any ideas? Thank you very much for your help.

have you checked your rotor for good magnetism? A weak rotor will not produce good spark

Not sure how to do that. The spark that I get is quite bright.