Pazon Ignition Elsewhere

[vibrac]

This is not Vincent related except that I am using a Pazon ignition system so may be of interest. I have fitted a Pazon ignition system to my 1958 650 Triumph and removed plugs to check it works correctly and it does. I also needed to mend the horn as the earth wire had broken in the loom. I fitted a new wire in the classic manner from horn button (earth) to horn and a live from the common connection after the fuse from the battery. On testing the horn (the plugs still being laid on the head) I noted a discharge, no a cascade, of sparks on the plug when I blew the horn. this occurs whatever the position of the rotor. How is this happening?

 

[Speedtwin]

Are you using an ignition switch with separate isolated circuits?
I have retro fitted high power electronic ignition to several machines and discovered the output being so high from the generator It was jumping the circuits in the original lucas style switches remedy was to fit electronic switch with isolated circuits designed for the electronic ignition.
Spoke to ignition folks they advised different switch.

 

[ClassicBiker]

At the risk of stating the obvious. With mechanical points, when the points are closed there is a dead short through the coil, when the points open the field in the primary winding collapses and causes the field in the secondary winding to collapse and the spark at the plug occurs. The points are replaced by the reluctor and hall affect sensors which tell the amplifier box to cut current to the primary winding of the coil and thus spark. If the voltage to the amplifier box drops low enough it might shut off power to the coils. Having had both Lucas Rita and Boyer Bransden ignitions on several bikes, I've noticed making and breaking power to the amplifier box either by turning the ignition key on and off quickly or disconnecting and reconnecting the battery quickly results in a spark at the coil. Perhaps the draw of the horn on a non-running bike is sufficient do do the same.
Steven

 

[vibrac]

, I've noticed making and breaking power to the amplifier box either by turning the ignition key on and off quickly or disconnecting and reconnecting the battery quickly results in a spark at the coil. Perhaps the draw of the horn on a non-running bike is sufficient do do the same.
Steven

Thinking about the advice above what about the effect of a low battery if the horn is pressed (It does need charging its at about 10v)

 

[ClassicBiker]

I would think it would spark the plugs. I think the draw of the horn would take to much from the amplifier box. My understanding is the amplifiers need a minimum of 9-10v to operate. Below that value and nothing works properly. Lights come on, horn blows, but the motor won't start easily if does at all. I think a good check in this case would be if the headlight is on and you press the horn button does the headlight dim appreciably. If it does I would say voltage to the amplifier is dropping below the minimum value to operate. A sure check would be to check the voltage across the feed to the amplifier with a multimeter and see what the voltage is with the ignition on and what it is when the horn button is pressed.

 

[Chris Launders]

I have a 1980 860 Ducati I haven't used for many years but unless the battery was in tip top condition it wouldn't fire while using the electric start but the millisecond you took your thumb off the button it fired up, obviously the starter was dropping the voltage too low for the electronic (Bosche) ignition to work, you operating the horn is probably doing the same thing, horns take a lot of power.