Hitchcocks Forum

I have a enfield bullet 65 and the 4 wire alternator is u/s and have been given a 3 wire alternator as a replacement by a friend , can I do this swop with out going to more expense . I would appreciate your comments, cheers ng

Pretty sure it would have been fitted with a three wire alternator from the factory

I could be wrong I often am

Take care Dai

PS more helpful answers will follow

If I remember, Sixty-Five's have a 4 wire alternator. One pair powers the headlight (only lights when the engine's running) and the other two do everything else via a rectifier and regulator.
Or do you mean 1965? In which case it would be a 3 wire.
Either way you could change over with a bit of re-wiring.

Bullet 65 not 1965
Yes 4wire alternator AC headlight
Said I was often wrong
Take care all Dai

If the original alternator rotor still has plenty of magnetism you can swap stators over. Depending on what colours the ires are you connect two of them together so that the alternator is constantly wired for full output, a bit like the Lucas RM19s on early British bike 12V systems. Is the three wire alternator Indian or Lucas? If you let us know what colour wires it has someone will tell you which ones to connect.

The whole output will now go through the reg/rectifier (consider a new one, they're not expensive), so you will need to play with the headlight wiring a little bit to make it suitable for for joining the DC system. The orange AC return wire now needs to serve as an earth wire, the AC regulator can be retired and you will have to have a good long look at the headlamp wiring in the switch gear and not make sure there are any stray connections left over to cause problems. I have twice wired Bullets for all DC using the kickstart Bullet AC/DC headlamp switches, and twice forgotten that the red and yellow wire to the switch must not be connected to anything. Not quite sure how this will work with the E/S switchgear from the Sixty-5, but I suggest you follow the Electra-X headlamp switch wiring diagram for this. Outwardly they're the same switches, but the Electra-X lights are all DC.

A.

Adrian, not sure this will work. I have always understood a 4 wire alternator is in effect two separate alternators in one. Two wire connect to AC regulator for headlight and the other two connect to regulator regulator to provide a DC supply for all other electrics. Is this not so? Are you saying twist the two wire that would have the AC lighting together and twist the other two wires together and then connect these twisted pairs to the two inputs into the regulator rectifier. I don’t think this will work. Richard

Pay attention, 007!

73a was asking about replacing his knackered four wire alternator with a three wire alternator. I was talking about joining two wires on the THREE WIRE alternator that 73a has been given, not the four wire alternator which he wants to replace. Indian alternators pre-1999 were copies of the Lucas RM19 (ish), which to give the full output required for 12V need to have two of their THREE wires (whose colours I could not remember) joined together, I would suggest using proper terminals rather than just twisting bared ends together... It probably already has 4.7mm bullet connectors.

The four wire alternators can be converted to put all their output through the reg/rectifier according to Pete Snidal's manual, but that's irrelevant here, since 73a posted that the original 4 wire alternator is u/s in this case.

A.

Check the rotor size I know one is slightly smaller and won't charge enough with the three wire stator (Don't ask)
When fitting the stator use the spacer pieces, it doesn't look right but if you don't you will bend your brand new stator (again don't ask) but hitting it with a 32oz dead blow hammer got it working

Probably easier to measure the inside of both stator's the rotor will be a bu66er to measure due to the magnets

Take care all Dai

Adrian .... yep should have read the post ...... dear god help me to engage brain before pressing the send button

tribonnie wrote: ↑

Wed Apr 08, 2020 7:27 am

Adrian .... yep should have read the post ...... dear god help me to engage brain before pressing the send button

Didn't you say

RTFP