BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: Old Biker on 29 June, 2017, 18:12:58

Title: A65 alternator
Post by: Old Biker on 29 June, 2017, 18:12:58
Hi All

I am in the process of getting my 1965 (with 12v system from new) back on the road. I have fitted it with a Boyer MK1V ignition kit and that works fine. However it seems I have an intermittent problem on the charging side and was considering changing the diode and rectifier for a modern regulator/rectifier. On looking for said replacement it appears that they can be either single or three phase, can anyone advise this "Old Biker" which my current alternator is likely to be? The bike is positive earth.

Cheers
Title: Re: A65 alternator
Post by: JulianS on 29 June, 2017, 18:52:38
More likley to be single phase. 3 phase came in in the 1970s.

If the windings are open not encapsulated than its definately single phase.

Windings were encapsulated in resin from sometime during 1967.

If the windings are encapsulated and there are 2 output wire then  it is also single phase.

If the windings are encapsulated and there are 3 output wires and 6 poles visible on the stator when view from inside diameter it is also single phase.

If the windings are encapsulated and there are 3 output wires and 9 poles visible on the stator when view from inside diameter then it is 3 phase.
Title: Re: A65 alternator
Post by: Old Biker on 30 June, 2017, 09:50:34
Thanks for the information Julian, most helpful