Print Page - 5 wire alternator

Title: 5 wire alternator
Post by: DAVE BRADY on 26 Sep, 2025, 11:59

Hi,

Many tears ago I had a stripped down B40 and i fitted a 5 wire alternator. In had it running with a coil from early Honda C100 Cub. Wires are red, brown, brown/blue, black/white and black/yellow. The black/yellow is the extra one.
The wiring diagram for C125T and C15S shows 4 wires.
The stator has the number 7197A 1166 and the rotor which I think was the standard one, has the number 05421 82.

Dave.

Title: Re: 5 wire alternator
Post by: iansoady on 26 Sep, 2025, 12:22

Is that for the energy transfer ignition system? I speak from a point of total ignorance.

Title: Re: 5 wire alternator
Post by: DAVE BRADY on 26 Sep, 2025, 12:31

Hi,

I would say yes. It seemed to work like a magneto.

Dave.

Title: Re: 5 wire alternator
Post by: Derek996 on 27 Sep, 2025, 09:34

This is the typical wiring for an energy transfer system on single cylinder bikes.

Title: Re: 5 wire alternator
Post by: DAVE BRADY on 27 Sep, 2025, 10:00

Hi,

In my service sheets 808J only shows 4 wires with black/yellow being the fifth one.

Dave.

BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: DAVE BRADY on 26 Sep, 2025, 11:59