Alternator wiring

Hi Dan,

According to the wiring diagram there are three wires coloured White, Light Green and Orange. To use as a 6V alternator the White and the Light Green connect to the rectifier(AC) and the Orange connects up to the headlight/ignition switches. There is a resistance wire in there as well which is switched in and out in place of a proper regulator. Use a modern electronic rectifier.

To use as a 12V connect the Light Green and the Orange together. The white wire is the common. But you need to make a few other changes as well such as fitting a Zenor and changed bulbs etc. I think al Al Osborn is the best man for eletrical queries and he can supply the likely parts as well.

Patrick

The correct wire colours on the coils should be Dark Green on the Switch side and Maroon on the CB side.

Looks like an exciting time with a multi meter chhecking wiring.

Hi Dan,

You might already have a good idea of how to test out the existing wiring but if your immediate intention was to just get the engine running I would simply leave the alternator wiring disconnected for the moment and try connecting a 6V battery into the system. It is wired as positive earth. Do this carefully in case there are any immediate 'shorts'. If all goes OK then check to see if you get 6V at the SW side of the coils with the ignition switch in the I position. If you have 6V at the coils the other coil wires go directly to the points - one wire to each set- doesn't matter too far which one. Just change the plug leads over to fire the correct cylinder.

If you have no power at the SW side and your battery is good suspect the ignition switch and try it in the E position. These switches have a habit of not working properly -internal contacts get dirty- but they sound and feel as if they are working fine.

Basically the system is pretty simple. If all else fails a wire from the Negative side of the battery direct to the SW side of the coil will get you ignition for starting. That is of course with the engine earthed in the frame and the battery positive earthed to the frame. But be cautious when connecting up as you never totally know what someone else has done to the wiring when it's obviously not standard.

Patrick

Ah, now I understand. I think the club spares do points and condensors if you go that way. I can't say about fitting the Boyer power box. If you do go the power box I would expect that wiring instructions come with it but I think you have to make the change to 12V which costs a fair bit with buying a Zenor diode and the special mounting heat sink etc or does the power box do all that in itself.

I have a Boyer electronic ignition on a Jubilee engine and I can't say it's much superior performance wise to the old system but it needs less maintenance. The Wipac alternator is rated at 50watt so you haven't got a lot of power to run the ignition and headlamp etc.and when I spoke to Boyer Branson some time ago they told me that the electronic ignition could take 30 - 40 watts to run in itself. But my Boyer Branson is an old one.

Al Osborn is the most likely person to tell you how to identify the existing wires on the alternator coils if no-one else replies.

Patrick

Boyer Bransden stuff is pretty good and their service was excellent in my experience. I see now that the Jubilee/Navigator are actually covered in their literature. When I got the Boyer electronic ignition it was a combination of the Commando 'black' box and the base plate from a BSA Bantam. This was a good few years ago. We were also using a Commando 'black' box on a BSA Starfire for racing (running a total loss system) and we always had to change batteries several times at a one day meeting. That was why I contacted Boyer Bransden about the current consumption and I was assured this was normal the current consumption now appears to have been much reduced,

Restoring a Jubilee costs about twice as much as restoring a 650SS and is worth very little at the end,!. cheapest bet is to buy a concours item in the first place but it's not much fun that way. I doubt if any of the rotors on eBay would fit the Jubilee as the centre hole is an odd size, not used on anything else as far as I know.

Patrick

On the matter of restoration costs at the October Stafford show I saw a very nice set of Roadholder forks - would fit the Navigator-on the stall of a well known 'budget BSA' trader. I asked how much and was told £950; I passed the friendly comment that was a lot of money to a poor man. The said trader (obviously an ace salesman) turned his back to me and said he didn't sell to poor men.

Strangely enough I didn't buy a new Jubilee seat from him that I had intended to buy.

I think the power box does it all, of course I could buy a 12v lucas alternator and go the whole hog

Alternators are not either 6V or 12V, their voilage is set by the regulator, in a crude 6V system this was set by the battery being 6V, the later improved 12V setups were regulated by the Zener. So your 50W wipac alternator will pump out 6V or 12V and in a 12V setup just like the lucas alternator will pump out more watts say 90W. So save some money and you can go 12V later without changing the alternator.

RE the above saga, pleased you didn't buy the seat. Also the figure quoted re Boyer consumption is a bit rubbish. Early RITA AB5 ignitions used lots of amps but everyother electronic ignition in common usage these days will only use a smidgin above standard coil ignition.

Now to save a long diatribe re Electronic ignition and 12V for ligtweights please get in touch via email alan@aloz.org.uk and the information sheet can be yours. Information such as no more Zeners available, Boyer Power boxes not as good as they should be, Boyer ignitions snags when fitting, you must have 12V, Retain 6V Wipac coils and more. The real facts about the resistor, snags with standard looms.......

Al Osborn.