Boyer Power Box Conversion

Hi Leonard, 

I have Boyer power boxes on four of my Norton's, one of which failed and prevented the battery from charging.

As the power box contains a capacitor (As well as a rectifier and zener replacement) it is possible to run without a battery, but in my case it was the battery that saved the day. Charging a battery every day will never catch on.........

My Commando is still fairly STD, electrically, save for the Mk3 Boyer electronic ignition fitted in 1989 and so far all good. Just need a good battery.

In the light of the Boyer power box failure in 2017, I decided to buy a power box from Al Oz, (who may comment), on my 57 pre FB Model 50 and to date no issues. However, this unit did not include a capacitor, but the good news is that the commando has a capacitor as standard.

Sorry I didn't keep my wiring notes but I did fit a charging light, (On my 650) wired through the Boyer PB and ignition switch. I think Al Oz supplies these as does Paul Goff.

Hope this helps.

I've got a Boyer Power Box on my 72 750. It replaces the Zenor Diode, the Rectifyer, the Ballast Resistor and the Capacitor although I did leave the Capacitor on for a long time. The first one lasted about 9 years before it conked out and the bike stopped charging the battery. I bought another one exactly the same as it was easy to do that. Best to fit it in a position where it gets cool air to stop it overheating. The wiring details come in the box from memory or if not wiring instructions I belive are available to download on the RGM website. I actually bought a new wiring harness from Norvil but realised it was designed for use with a power box and had no wires for the bits that the power box replaces. I'm more than happy with it. You could get the one from Al Osborn or phone him first  01953 884681 for advice as he is very helpful and knowledgable. I have to say a power box does tidy up the electrics a bit.

Some factors-The Power Box as named and sold by Boyer Bransden, I used to sell, then it became too expensive and failed occasionally. So I moved to the A  Reg.

Don-The Power Box does replace the rectifier and the one or two Zeners. It has nothing to do with the Resistor-(ignition) The Capacitor (2MC) is there for emergency starting and running without a Battery. The A Reg does not have one so you have to fit another IF you want that facility. The Power Box does have one, having two is not an issue. Wiring instructions is next to nothing (and in the box). Two yellow wires in. A Black and Red out.

I have run the Boyer Power Box on two of my Nortons for 30 plus years and never had a problem.

One runs with a battery and one without. (that one just needs more of a boot to start).

It simplifies the wiring especially when fitted with a dual output coil, also both Boyers.

If you have a flat battery and coil ignition, the Boyer will get you going with the kick-start but disconnect the battery first or the Boyer output ends up disappearing into the battery rather than firing the ignition.

Just take the fuse out. Easier.