Alton and Boyer?

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.

Dave

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.

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.

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

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.

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.

Cliff.