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Alton and Boyer?

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Alton and Boyer?

Posted by david_broadbent at November 24. 2018

I have run a Boyer ignition system and powerbox on my 2A Commando for the best part of 25 years without fault. I even have a spare set I bought once because I thought I had a problem, but I was mistaken - so it's still on the shelf.

Now I am seriously thinking about an Alton electric start conversion, but I keep hearing that I'll need to replace the Boyer because it is somehow not compatible with the Alton. Is this actually the case? I seem to hear nothing but tales of woe from subscribers to this forum about all of the more modern equivalents so it's not a move I'm keen to make.

Do I really need to ditch the Boyer?

Re: Alton and Boyer?

Posted by dave_taylor at November 24. 2018

The Boyer in its day had little competition and indeed was/is reliable. However it does have two design faults.

1, When the system voltage drops, I think to less than 11.5 volts, the Boyer will over advance resulting in kickback. ie When when the stater loads the battery.

2, Boyer does not have true advance curve rather a straight line of continual advance resulting in an ignition compromise. Not a problem with a starter just something to think about if you do buy a new EI.

Modern electronic ignitions mimic the old AAU and tolerate low voltages.


Re: Alton and Boyer?

Posted by john_holmes at November 24. 2018

If its a mk3 Boyer then change it for a boyer mk4 or a pazon. The Alton's anti backfire is some nylon pucks, to save the motor they break, then you have no starter until you replace the pucks. The mk3 Boyer over advances at low voltages creating backfired so best replaced, the mk4 and the Pazon over advance at much lower voltages.

Re: Alton and Boyer?

Posted by mark_woodward at November 25. 2018

The Pazon system has a good reputation. I personally have a Tri-Spark Classic Twin system on my 920 Commando Mk2A fitted with an Alton starter. The Tri-Spark system has an 'anti-kickback' feature (which I gather the Pazon also has) - this retards the ignition a little more than 'normal' for easy kick (and electric) starting; I can vouch for the effectiveness - starting 'on the button' is instantaneous.

Re: Alton and Boyer?

Posted by francis_vidril at November 25. 2018

The manufacturer of the ALTON E.STARTER advise NOT AT ALL L'ALLUMAGE BOYER.

Re: Alton and Boyer?

Posted by ashley_cutler at November 25. 2018

The Pazon will backfire, it is not directional like the Tri Spark. That is why the Pazon will fit early Commando and the Tri Spark system retails one type for early and one for the later Commando's.

Re: Alton and Boyer?

Posted by cliff_appleton at November 25. 2018

I have a an older Boyer and a power box. I fitted an Alton earlier this year and have had absolutely zero issues (apart from the wire from the starter switch broke off the solenoid, which I was able to repair myself). The bike comes to life in less than a revolution. The older Boyer's are sensitive to low battery voltage when they will over advance and backfire. Some folks have fitted cheap voltage regulators which ensure a 12 volt supply to the Boyer.


You can read all about the installation on Access Norton under the thread heading "Into the unknown"

I bought my Alton kit from Gordon at Spike Island motorcycles. He seems to be the cheapest supplier that i could find, and has one on his own very nice Roadster.


I hope that helps.


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