Would the below picture be a war time mag or post war, i am reading a bit of conflicting information on whther this is a slack cable advance or the other way, i am just timing the bike up and what i have read doesnt make sense.
Tod without seeing the mag from the side, I can't tell if it's war time or post war. But either way both function the same. What you have there is a slack wire advance which is not factory correct but will work just the same. So when timing it, push the handlebar lever away from you for full advance (assuming you have a correct mag lever fitted...picture if you're not sure)
As it happens the slack wire advance is a better idea as it will default to full advance if the cable were to break. The only WD bikes that employed it during the war, were Royal Enfield, but I think most others followed suit, post war. Ron
The dynamo is the wartime type...The magneto may be post war...It certainly has the later 'slack advance cable' set up that wasn't introduced on the M20 until the mid 50's..However, it is possible to change the end casting.....I'd need to see a photo without the dynamo fitted to determine whether the main body casting is a wartime type...Ian