General => Douglas Motorcycles - General Discussion => Topic started by: Pallijen15 on 17 Dec 2018 at 13:20

Title: Magneto slip ring
Post by: Pallijen15 on 17 Dec 2018 at 13:20
Hi, I am wanting to remove the magneto slip ring because it is sticking. Do I have to upset the points or can I leave them in situ? I would like ideally to remove the contact points housing but I think this would necessitate removing the points first. Also, the engine will not cut out from the handlebar cut out button. Wires are all connected. Is this a fault at the magneto side? Thanks, Paul J
Title: Re: Magneto slip ring
Post by: eddie on 17 Dec 2018 at 14:19
         When you say 'slip ring', do you mean the cam ring? If so, you will have to remove the points assembly first. Just undo the centre screw, then wriggle it - the points assembly should come free from it's taper. Removing it will not upset the points setting. With the points removed, you should be able prise the cam out of the housing using a couple of screwdrivers under the step on the inside of the cam. When replacing the cam ring, set the timing to half advance and make sure the cable fitting engages with the slot in the outside of the cam ring. Be careful when you refit the points - there is a small brass key formed on the taper which must pick up in the keyway in the armature - it is easy to press it back in if not correctly aligned - thus destroying the timing of the points.
   Should the cam ring be stubborn and not move, you will have to remove the 2 screws and the post for the cover retaining clip in order to remove the end plate from the mag. There will probably be some shims under the end plate - make sure you replace them. You will probably need to warm up the end plate to free the cam ring - do this in a pot of boiling water - do not try to heat it with a torch - the plate is zinc based alloy and can be easily wrecked if overheated.
   With regard to the cutout not working - check out the wiring to the points cover. On the inside of the cover there is a screw that secures the wire - it should have a point that penetrates the insulation on the wire, thus completing the circuit. You can do an easy check with a bulb and length of wire. Connect the live side of the battery to the side of the bulb, touch the end of the bulb on the carbon brush in the points cover and press the cutout button - the bulb should light! If the bulb doesn't light, you have a wiring fault - either at the screw or at the cutout button - make sure it is properly earthed to the handlebars. It's surprising how many owners try to 'improve' the fit of the button by seating it on tape (and then find the cutout doesn't work!

Title: Re: Magneto slip ring
Post by: Pallijen15 on 17 Dec 2018 at 14:46
Thanks Eddie, yes, cam ring