1956 Mod 50 mag removal

The bolt that is turning is a long bolt that passes through the magdyno platform and both engine plates. You will need to put a spanner on the corresponding nut on the drive side of the engine. When you get round to refitting the mag don't overtighten the locking bolt (already removed) as it goes into a tapped hole in the mag platform which is easily stripped. The sprocket will not pass through the hole in the rear of the timing case so will have to be removed. If the chain has a split link it is probably easier to remove the chain and then apply a small 2 leg puller to the sprocket. Another option is a short lever with a hooked end that grabs the edge of the sprocket. It can then be levered off against the end of the mag armature shaft. Do not be tempted to lever against the timing case as you will probably damage it. I think the lever method may already have been described more fully on this site.

Ian McD

Ian Soady posted a link to a simple sprocket puller earlier this year. Easy to make and can be used with or without the chain in place.

https://www.nortonownersclub.org/noc-chat/technical1-singles-forum/696198693?b_start=0#971787453

Hi Terry, attached is a picture of the Beta 1506 puller that I use for the mag sprocket. I think I bought it from Molnar Manx but you might be able to buy direct from Beta Tools.

http://www.beta-tools.co.uk/online-brochure/

http://www.manx.co.uk/index-2.html

Ian McD

Hi Terry,

I think Ian MacD's second method is the easiest, but there are a couple of things you may want to do first. If the bike is new to you and is running well it would be worth measuring the timing so you have that information when you put it back. The first thing to do is remove the dynamo,secondly undo the mag sprocket nut which is a normal right hand thread. Turn the engine backwards against compression, use a 5/16th Whitworth ring spanner and give it a sharp blow with a decent size hammer. There is a gap between the mag and the timing case and you need to put a suitably thick piece of aluminium strip or hard wood in this space so the case can't flex. Using a large tyre lever, the flattype you used to get in Halfords etc. and hook the end with the 90 degree bend behind the sprocket and give it a quick shove against the caseand it should break the taper fit as the pressure is on one side. Next remove the advance/retard cable and plug lead. After you've done this you can thenremove the small lock bolt then remove the main bolt, the one that's been turning round. You will probably have to loosen one side of the rear engine plates as the mag mounting plate can be a tight fit and get wedged between.

Regards, Richard.

I would never lever against the case even if it was supported as it's so easy to break the timing chain extension.

The puller described by Rick Parkington which I linked to in my post referred to above is very easy to make and only needs the use of an electric drill. It worked well for me.

I'm surprised you can get the leg of that Beta puller under the sprocket / chain - I wouldn't be able to on my ES2. The puller I used to have was pretty cheap and nasty but the legs were just made of 1/8" or so flat strip bent to a right angle. No good for anything meaty but enough for mag sprockets.

Hi Ian, no problems using the Beta puller on my (and my brother-in-law's) 19S, also my CS1. Maybe it depends on the number of teeth on the mag sprockets? There are variations, 15T & 16T. The larger sprockets would reduce the available clearance. I remove the chain before applying the puller.

Definitely with you on not levering against the timing case. You might get away with it but I wouldn't take the risk - not that easy to find a replacement case. Photos in the puller article show what can happen.

Cheers, Ian McD

I prefer an endless mag chain so it's tricky to get off without the sprockets.......