Hi all I was just wondering if anyone has some picture/photos of how a dynamo is wired up I think mine is wrong it’s a 1940 wm20 twelve volt?.

Muchly appreciated

email (option): dewheelie@gmail.com

12 volts? I wonder why? There are only two wires on the dynamo. D & F. Which simply go to the D & F terminals on your regulator. It would originally have been Neg earth and the dynamo should be "flashed" accordingly.

Ron

email (option): ronpier@talk21.com

Thank you for that I just wanted to double check because I haven’t worked on a dynamo before and I put a new coil in it, just forgot the wiring plan just bad pixlating pics on the web.

email (option): dewheelie@gmail.com

I ment the inside of the dynamo ie how it is wired by the way.

email (option): dewheelie@gmail.com

I've just tested a dynamo that I put a new field coil and armature in.
The output is pitiful :cry:
Not even enough to wake the DVR2P regulator.

Mark

email (option): pes.sales@btconnect.com

There's a lot to be said in favour of the old Lucas regulators...They were very reliable back in the day and were unaffected by short curcuits etc..
Most of their bad reputation was accrued when they were still in use long after their intended lifespan...I still have one that is working OK...

I used to get them restored by someone who, sadly, eventually stopped doing it as he couldn't get his customers to pay a realistic price for the (labour intensive) service....There's nothing that can be done about the dynamo output, it is what it is...The only option is to run a later unit that has a higher output and live with the slightly different appearance...If the early version of the 60W dynamo is used that still has a bakelite end cover and it doesn't look out of place (though no good for the purists)...These can be run at 12 volts but bulb ratings etc. still have to be sensible and as nothing is for nothing the dynamo has to be running at a higher speed to 'balance' the system...I ran an M21 like this for about 8 years as a ride to work bike and the system was reliable (I didn't alter the dynamo windings)...From memory I think I ran a 35W halogen headlamp bulb which provided adequate output for the unlit Devon lanes....Ian

email (option): ian@wright52.plus.com

email (option): ronpier@talk21.com

Thank you ever so much another question I have is I have both 12v and a 6v magnito the 12is fully functional it’s just I am hearing that the 6volt is the better of the two any thoughts on that?.

email (option): dewheelie@gmail.com

To my mind, a magneto generates a spark for the spark plug and has nothing to do with battery voltage at all. You don't even need a battery with a magneto to run the engine. Ron

email (option): ronpier@talk21.com