Hi all , got an over charging problem bsa wm20 on start up the meter on headlamp goes up to the +8 (right side ) put headlamp on drops down below 0 then bring the revs up and needle goes up towards the 8 again . If no light's on it miss fires lights on and runs fine , my question is have i fault in the dvr2 or in the mag . Phil
The charging system for the lights is powered by the dynamo and the spark for ignition is provided by the magneto...The two are completely unconnected at any stage of their operation...If you have a problem with the engine misfiring it's most likely to be either fuel supply, carb settings and/or overall condition... An electrical or mechanical problem with the mag or spark plug/ht lead issues are another possible cause...
In the case of overcharging of the lighting system, regulator failure is the most likely cause or a completely dud battery....I would advise you to acquire a full grasp of how to fit an electronic regulator before attempting the job as it is easy to (terminally) damage one via incorrect fitting procedures....Ian
Hi Ian thanks for the reply it's all been running lovely since fitting a couple of years ago so know its not fitted wrong and i did think that mag and dyno are separate items so the misfire seems a bit weird, when out on the bike other day and volt gauge shot up I have checked with a volt meter and climbs up to over 8v on tick over I will try a new regular cheers
I have seen problems similar to this with the ignition not working correctly due to the generator. And it was on a Magdyno bike, a 1936 Triumph.
If the magneto armature is moving around due to the bearing insulating cups being bad, turning on the lights will load up the generator armature which is driven by the magneto gear and it can change the ignition timing.
No guarantee this is your problem, but something to look for. Remove the timing cover on the engine and see of you can move the magneto armature. If you can make it move up/down, side to side you need a rebuild.
It happened to me whilst riding my WD/CO around Dartmoor some years ago. The paper insulating cup for the mag drive side bearing disintegrated and gave me no end of trouble. Ron
