[AsFarAsIGet]

Hi all!

I just received my most recent delivery from Hitchcocks. Amongst others a one unit rectifier/regulator. But when I open up the box and read the instructions I became quite puzzled. The instructions mention a 2 wire stator. My bike has 4 wires coming out of the stator. According to the fitting table on the reg/recs page in the parts book (https://accessories.hitchcocksmotorcycles.com/accessory-shop/Powerbox-cat/37670) the reg/rec is supposed to fit my 2002 India home market Bullet 500. I have attached a photo of the instructions.

What am I not understanding? Or have I just ordered the wrong part?

Can someone help me please.

(I have also sent an e-mail to Hitchcocks in hopes of an answer from there as well. It's just that you guys often are so fast and accurate in your replies that I give it a shot here to

/ Ruaridh

[AzCal Retred]

The Bullet stator has 3 coil pairs. 2 pairs are paralleled, the 3rd pair is "stand alone" sorta. All coils "rise & fall" at the same time, only single phase AC is available. The rotor magnet configuration and stator coil layout determine this.

In the wayback 4 wires exited the stator. Originally in the dim mists of time one pair of coils ran AC lights and the second pair ran thru a hi-tech (for 1960...) silicone rectifier to make DC for battery charging. A switched shorting system took care of Hi & Lo beams, a mechanical regulator took care of charging.

In the 80's? tech caught up, the stator became 3 wire (common leg, a 2-coil output & a 1 coil output). The outputs paralleled outside of the cases and 2 wires ultimately went to the newfangled solid state Reg/Rec boxes. The bikes were all DC. 60 mighty watts were available for your DC needs, 20 watts per pair of coils.

About 2000 the 4 wire system made a return. This time the paired coils went to an AC voltage regulator, then to the headlight switch. No complex headlight shorting switch was necessary as the AC regulator took care of all needs, up to 40 watts of incandescent (AC/DC!) headlamp. The second pair fed the battery charging reg/rec as before on the 3-wire systems.

For a 4-wire system, basically it becomes "2 coils" as before. The AC-intended coil pair are the same as the DC coil pair. This means that since they are paralleled, the coil resistance is 1/2 of the single coil. So we have a way to tell who's who. The higher resistance lead pair is the battery Reg/Rec pair, the lower resistance pair is the AC Lighting Regulator pair. The two pairs are electrically isolated, so only one combo of wires give you an ohm reading for that coil. One pair will be about double the Ohms of the other pair, that will be the reg/rec pair.

You CAN parallel these coils to mimic the previous 3-wire 60 watt system. To do that you'd need to:
1) identify both pairs. tape mark one coil pair black & the other pair red. Put an "X" on one black and an "O" on the other black. Do the same to the red leads..
2) Connect and test to determine "instantaneous polarity".

Coils are like batteries. Connect head to tail and the voltage is double, head to head and the voltage is way less.

With all 4 leads "open", not touching anything, connect the red "X" wire to the black "X" wire. The unconnected (open) leads go to the voltmeter. No current will flow, this is a voltage test.

Start & fast idle the machine, read & record the AC voltage between the open black & red "O" wires.

Each pair will generate between 15-40 volts. Voltage is RPM dependent. Use the same RPM for each polarity test.

Swap the red coil pair leads only, use the same black "X" lead. Retest & record at the same RPM.

The highest voltage connection was a tip to tail (X to O). The lowest voltage reading will be from a  "tip to tip" (X to X) connection. Remark the red leads as necessary and retest to PROVE what you think you know. High reads X to O, low reads X to X.

Good hunting!

[stinkwheel]

You should have two violet wires, a black and a red/yellow connecting to the original reg/rec combo.

The violets go to the two yellows, the black goes to the black and the red on yellow goes to the red on your lucas one.

[AsFarAsIGet]

Thank you so very much for your replies. Now there is hope again

[Adrian II]

The Indian 4-wire alternator stators can cause confusion.

If your alternator manufacturer has stuck to the RE(India) factory colours, there will be two purple wires, a yellow wire and an orange wire.

Two purple connect to the two yellow wires on the reg/rectifier as explained above, the yellow and orange wires connect to the AC regulator for the headlamp.

What messes things up is where pattern parts suppliers start using different colours for the wires!

It is possible to combine both outputs from the stator and feed the whole thing through the one reg/rectifier, and with a little bit of re-wiring for the headlamp, you can have an all DC lighting system.

A.

[Raymond]

It is possible to combine both outputs from the stator and feed the whole thing through the one reg/rectifier, and with a little bit of re-wiring for the headlamp, you can have an all DC lighting system.

It's not very difficult - with assistance and encouragement from this forum, I did that and made the bike fully DC. Partly to make it easier to replace the plasticky switches with Chinesium metal ones - prefer the look. Also swapped the original stator for a higher output Lucas one and again not difficult to learn what you need, identify the correct replacement and fit it.

Sorting the electrics has been the main thing on my Bullet, most unreliability problems are electric, gives me confidence knowing the wiring has been simplified, slightly beefed up, brought slightly more up to date, wired in and connected up meself so at least if it plays up I slightly understand enough to fault find.

[Adrian II]

I fitted a 4-wire Indian alternator on my UK-built 350 Bullet, the Lucas 2-wire stator fitted by the previous owner wouldn't centralize properly over the rotor (the Indian stator lined up just fine!). The alternator I fitted looked quite a powerful one by Indian standards with a wider than usual rotor and stator coils - was this meant for an E/S Bullet, perhaps?

For some reason four of the six coils were dedicated solely to the AC headlight and two for the reg/rectifier to power everything else. Hmm, experiment coming on. WHAT IF I were route the AC headlight supply through a reg/rectifier and battery for ALL the lighting (hey, it's most of the alternator output, and I'll be using LED bulb replacements), while I plug the two purple wires with the rest of the alternator output into a battery eliminator type/reg rectifier (i.e. with built-in capacitor) and use that only for the ignition?

Well, it kind of worked! The only problem was that I was using a Pazon electronic ignition, and despite Pazons claiming to work better than Boyer ignitions with lower voltages, it needed some quite enthusiastic kicking over to get a decent spark. If I had been using points instead of electronic ignition in the distributor, it might have made bigger sparks at kick-over speeds.

Anyway, I gave up on that, removed all the coil ignition stuff and persuaded an old BTH racing magneto to fit. Happy zappy at kick-over speeds, now...

A.

[AzCal Retred]

That's why I added the "how to determine instantaneous polarity(IP) tip to tail" write up. All 3 coil-pairs rise & fall the same. Out of phase IP will be 180, so overall voltages subtract.

[Adrian II]

This assumes (as I always did!) that the four wire stators have three coils for the AC headlight and three for the rest of the electrics. The Snidal manual reckons it's FOUR for the AC headlight and only TWO for everything else, a quick check of my non-encapsulated stator wiring revealed that he was right - in this case! Would that have made a difference?

Given the availability of different aftermarket stators (Minda versus Swiss, or who knows these days?), I suspect you could have either four plus two OR three plus three.

In the wayback 4 wires exited the stator. Originally in the dim mists of time one pair of coils ran AC lights and the second pair ran thru a hi-tech (for 1960...) silicone rectifier to make DC for battery charging. A switched shorting system took care of Hi & Lo beams, a mechanical regulator took care of charging.

Way, WAY back the earliest Indian-built Bullets still had a Lucas MO1 magdyno for sparks and lights, these certainly would have had the old electro-mechanical voltage control or CVC boxes for the 6V dynamo.

On going over to the alternator, from all the wiring diagrams I've seen, they simply copied the standard Lucas 3-wire, 6V positive earth/ground package as used on (e.g.) my old BSA C15. No separate voltage control unit on these, it just relied upon switching the coils in and out for full output for when the headlight was in use. The old 3-wafer silicon rectifier was standard Lucas kit on all alternator British bikes for years afterwards, even after the British factories went for 12V systems and zener diodes for the voltage control. The only un-rectified AC function on the 6V system was in the emergency start position for use with a flat battery, which allowed the alternator to power the coil directly, with a dire warning to turn the ignition switch back to the normal run position immediately the engine fired up, or else! Not sure if Enfield India ever incorporated THAT feature.

By the time Chennai went for the 4-wire AC headlight thingy, Lucas had been producing three phase alternators for some time, as well as higher output single phase alternators. Something like this would have made more sense if the old alternators were getting a bit weedy, the new ones had the same fitting, but no, let's confuse as many people as possible with two separate systems on the same bike. I think the penny dropped with the 500 AVL models, and the factory has been fitting Japanese-style 3 phase (permanent magnet) alternators on all new models ever since.

Someone, somewhere knows exactly why a separate AC headlight system made sense. I would have thought that a battery-independent IGNITION system would have been of greater value. The factory also thought of this with the CDI ingition used on some of the home market 350 models, but say hello to the SIX wire alternator...

A.

[michiel]

The 4-wire alternator arrived when it became compulsory to drive with lights. The coils for the light (AC) supply approx. 60 watts. Reduced to 12 volts by an AC regulator.
The other coils, which charge the battery, deliver approx. 80 watts. Through regulator/rectifier (DC) to charge the battery.

[Adrian II]

We know the 4-wire alternator runs two separate systems, and you can still ride an old AC headlamp/Minda switchgear Bullet with the lights off, I think it's only with the very recent (in RE terms) Euro 4 models that the lights on/off switch has disappeared.

What I was wondering was that, if more power was needed for more headlight use, why not simply fit an up-rated version of the existing alternator? The Indians could have manufactured RM23 or 24 stators under licence. We can over-complicate things (even without legislation).

A.

[stinkwheel]

AC headlamps are usually used when the alternator output isn't really high enough to put charge into the battery faster than the headlamp is taking it out. I suspect bullets are a borderline case. Then they make sense, all the DC lighting is intermittant so there's time to charge the battery between uses and they have slightly more constant output than the ignition draws to keep the battery topped-up. Seperating the lighting means you aren't going to suddenly splutter to a halt when riding in the dark.

AC is a good idea for lighting because the DC lighting dumps half the power straight off the bat to get the DC waveform. The AC uses the full wave and so utilises double the output the same coil could generate on a DC output. I agree though, it's a silly way of using a 3-phase alternator, the output should be enough to use straight DC for everything and many people have done this successfully (although have they ridden the bike in the dark for a protracted period??). I wonder if some of the early ones were more marginal in that respect.

Honda still use direct lighting on their small scooters/mopeds, so the headlight only comes on with the engine but have rather cleverly made the headlamps positive earth and the rest of the electrics DC negative earth. So the battery charges in the normal way from a single phase AC output via a regulator/rectifier. The clever bit is the negative half of the waveform which would normally be wasted via a diode arrangement is sent to power the head and tail light with an AC regulator built into the box of tricks. This complicates the wiring a fair bit BUT gets twice the useable power out of the alternator.

[Adrian II]

Now of course we also now have viable LED replacements for traditional headlight bulbs (for DC, at least) which use less power and give older alternators (and dynamos) an easier time. Not legal on post-1985 vehicles in the UK at the moment, maybe so in other countries?

A.

[stinkwheel]

LED bulbs are fine in the UK providing they conform to the beam pattern regs. Or they were this time last year anyway. And frankly, if they do, how would you know there's an LED in there anyway?

They of course won't work with AC lighting. Although interestingly, they do with the small Honda arrangement I mentioned above (which is something I'll seriously consider using on the next bike I have to build a loom from scratch for) because it's halfwave AC. Can't use an LED stop and tail light though because it's both positive and negative earth (wrap your brain round that one...)

[Paul W]

Yes, UK’s DVSA have allowed LED replacement bulbs for motorcycles since 2021, provided they comply with the existing regulations for light pattern and dip etc.

https://www.tomcc.org/Home/News/06ea40642b2f4d0f93ab9bd2025938dc#:~:text=The%20UK's%20DVSA%20have%20reversed,not%20be%20an%20MOT%20failure.

Strangely, they’re still not allowed for cars, though.