Removal of a Magneto/Dynamo BMWR12

[spider rust]

I have a dilemma, I am in the process of stripping down my engine, unfortunately the Mag/Dyno chain has no clip link, I have un clipped the cam chain but cannot get a puller onto the sprocket and am unsure if this is a one piece sprocket with 2 cogs on it, one for the mag/dyno and one for the camshaft. Also its impossible to lift and angle the mag/dyno to remove the chain.

Any advice is very welcome.

[Ian R11]

Can you grind the top off two chain links, remove the outer chain side section and remove the rest backwards like removing a split link?

[VintageSalesandRestorations]

Remove the sprocket from the magneto, back the nut off about 2 turns and use a puller to break it free from the mag shaft. Then remove the nut and sprocket from the mag.

[Beemer54]

I'd go with Ian's suggestion - using a dremel to cut through the outer link. I suspect you wouldn't be able to slide the rest backwards far enough to get it out though. You'd almost certainly have to push it a bit then use the dremel on one of the pins. All very fiddly.

First though I would triple check that there is no split link in the chain. I can't imagine how it could be assembled if this was an endless chain. Mating up the magneto with the sprocket in situ would be a nightmare. You'd be sure to risk dislodging the woodfruff key and having it fall into the engine.

I'm sure you know this anyway but the spring clip is on the INSIDE of the chain, facing the magneto. If you haven't got enough light shining down there then it's easy to miss.

[Peter]

Hi Spider - I was about to tell you exactly this, sorry for the delay and I couldn't believe it when I found mine on the inner side. I'm sure there is logic in this set up somewhere. I was trying to take the magneto off, suffice to say its with the mechanic now.

Cheers

[mdunn]

Don't cut the chain!!

1.Loosen the top strap on the mag
2. Remove the two small bolts on the top cover( not the front cover).
3. remove the top cover
4. Take a piece of wire(coat hanger and hook the chain, tie it off to the dampner).
5. Tilt the mag forward and use your finger to loop the chain off the sprocket on the mag.
6. Pull the mag backwards and off

Your done...

[spider rust]

Thankyou all, its off! That was the easy part, unfortunately its been got at by some idiot in Australia.