Bronco 125 No Spark Issues

[ducwiz]

The wiring diagram shows clearly, that the Bronco runs with an "AC energy transfer ignition". This system is often wrongly called "AC magneto". For better understanding I linked to 2 papers by Gordon Jennings:
https://mega.nz/file/ixhnnDZQ#CudhNT4F01uYfZeA8YQVM1GzsCHN_ZKPyHQaoL3xD_g
https://mega.nz/file/z5R3TaAA#QAhtV4DCYQ4Mrsmm3ebjV7gh8vrv2TT59fs-QhrpVkE

The diagram also shows that the ignition circuit is totally independent of any other electrical part in the battery/charging/lighting circuit. The "kill switch" mentioned by JimF is intergrated into the key switch. The corresponding (upper) pole shorts out the whole ignition circuit in the OFF position. The other pole switches the battery-powered system part exclusively.

Hans

[mtraikov]

Thank you everyone for the vast knowledge you all possess and are will kindly willing to share and provide to maintain this community. It’s really heart warming to jump into a new specific moto community and email/post with people that have the same mindset.

after taking everyone’s suggestions and advice, I have got the bronco fired up!

I will definitely make a toast to you guys at the wedding.

For anyone reading this in the future -

There is only one lead on the hot side of the HT coil. It is a light green wire, it goes up to the headlight switch, back down to the terminal block by the battery, and continues down into the condenser/contact breaker behind the flywheel.

I removed the flywheel (27 x 1.25 RH threaded extractor. Amazon seller has it). I cleaned the area with electric cleaner wiped away all the dirt etc. I cleaned the points with an emery board (this is probably what fixed my no spark issue). Cleaned the magnetic parts of the flywheel. Put it all back together. And it fired up.

The spark plug cap originally also had a long needle that is pressed into the plug wire to make contact with the wire. Mine had a much smaller one that appeared home made. I bought a used coil online and it came with it, otherwise I wouldn’t have known. So I swapped that out too.

Hope this helps someone in the future who is searching and reading as I did.

Mike