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Boyer Powerbox

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Hi there - just finishing up a Commando with twin headlights and have fitted new alternator (150w two phase) and boyer ignition.

I was going to replace the rectifier with the newer type - but not sure what to do with the zener diode which I have read is limited to 100w?

I havebeen looking at the Boyer power box - will this take out the rectifier, the Zener diode and the capacitor?

Is there a better option?

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Hi Steve, in a word - yes. There are quite a few rectifier/regulators on the market - most are pretty good but ensure you give whichever you opt for a bit of ventilation or, at least, bolt it to a good metal surface to act as a heat sink.

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Thanks Mark - I will try the power box and figure out best place to mount it, bike has a fairing so maybe under the battery tray in front of the horn.

I thought it would be relatively easy to replace rectifier/zener diode but was not sureif it also eliminatedthe 2MC capacitor. Steve

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It does eliminate the 2MC but the one inside the powerbox is the same quality and likely to fail as frequently as the 2MC ie it ages. It then, depending on how it fails, just becomes a useless black box or a combined ignition reg/rect. Better to go without the powerbox and fit EI plus a combined reg/rect with a good capacitor that you can get to and change when it fails as they all do.

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I have Boyer power boxes fitted to most of my bikes but the one on my ES2 failed on the way to the IOM MGP this year. Poor Joe Lucas got the blame but turned out the Power Box failed and did not allow the battery to charge from the alternator. I sent it back with a cheque but will have my cheque returned as they have already told me it is knackered.

This was disappointing (Would have been worse if I missed that boat) as I never had a Boyer product fail before.

I understand our Mr Osborn sells his own unit. Since the new box for my 57 model 50 is now on the ES2 I rather thought I'd try the Osborn unit.

Anyone tried one of these alternatives?

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I also had a Boyer Power box fail on route to the IOM (in 2007). Boyer posted one to me while on the island for a large amount of money. That replacement failed a couple of years later. I then bought one of Al Osborns (A.O. Services) regulator/rectifier units combined with one of his capacitors (his replacement for the 2MC). I've not had any problems since. I recommend the A.O. Services "A-Reg One" Regulator/rectifier unit. I believe it can be used on systems up to a maximum 180W.

Hope this helps, Alan

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Previously steve_nairn wrote:

Hi there - just finishing up a Commando with twin headlights and have fitted new alternator (150w two phase) and boyer ignition.

I was going to replace the rectifier with the newer type - but not sure what to do with the zener diode which I have read is limited to 100w?

I havebeen looking at the Boyer power box - will this take out the rectifier, the Zener diode and the capacitor?

Is there a better option?

I'm using one that RGM sell. Very cheap and unbranded. Can't be any worse than the expensive ones?

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Further information-the above is about right and I can confirm after having spent some 40 yrs in selling these items. I sold the Boyer unit many years ago but eventualy stopped asthe failure rate andthe cost both increased.Within the last few years I have been selling a product sourced in China that is lot cheaper and a bit more reliable. As per Alan T above. The further service Ioffer is also to be able to test these items.

In fact the original rectifier and Zener is still a viable system, despite its age and the fact that the Lucas Zener is no longer avaiable. (alternative Zeners are NOT up to the job) But as above once you want greater than the 100W capability of the Zener then you are in trouble.

The 2MC capacitor, yes the Lucas ones do seem to faileventualyand the Boyer one fails, but the one I sell has yet to prove unworthy.

There was alot of interest in the use or not of the 2MC some years ago in Roadholder. My point of view is that it is NICE to have but not esential. Very nice to have if you want to run without a battery and I can prove that having the capacitor on the 6V reg/rectifier actualy increases the charge current by reducing the ripple.

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Hello.

Please forgive my total ignorance here, but Iâm trying to work out how to make my mkIII (which I âinheritedâ from my uncle a few years ago) more useable.

My current issue is charging. And I think the problem boils down to the Boyer power box - and Iâm wondering what the best alternative might be.

My problem is that it only sends power to the battery over 2000 revs. And Boyersâ stance is that thatâs just the way it is and I need to ride harder. But I donât really want to given I mainly use the bike round town (and the r built engine isnât completely run in).

Can anyone suggest a âdrop in and replaceâ solution that has more flexibility/ adjustability?

thank you in advance

Felix

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The revs needed to start the charging process depends on the load, so with all the lights on it needs more revs than running lights off. Regardless of that at tick over the battery will not be charging and 1500 to 2000 revs sounds about right, its the alternator that produces the power not the boyer. So if you need to charge the battery after a ride look at the magnets in the rotor or upgrade to a 3 phase stator.
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Thanks, John

Thatâs with no lights on. And thereâs no power back to the battery until clearly above 2000. I understand what youâre saying re idle. But thereâs a big gap between the two the bike runs happily in.

Re the alternator, yes. I had been under the impression though that the current routed back to the battery via the power box which in turn regulates/ controls it.

No?

appreciate the help.

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In my view, the early versions of the Boyer Power Box were defective in that they failed to supply sufficient voltage to the battery. Whether newer versions have corrected this I have no idea.

Far better to use one of the many other versions of regulator available, and if you need help then go to Al Oz because he can supply them.

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All above is correct, but a few things to add. I can test regulator/rectifiers and Zener diodes. I can also test stators and rotors (for magnetism/output) so there is no excuse to guess with the charging of any British (Lucas or Wipac)alternator bike.

One trick that all of you should be aware off is if your reg/rect appears a bit low and/or the alternator is suspect (alternator test on my web site) then you can replace the reg/rect with a basic bridge rectifier. (I sell them too) Start the bike, does it charge? problem sorted. Only don't go for a long ride with your lights off or you will tend to over charge the battery. For a short test things will be fine.

 


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