MAg cut out

[Devlin]

 On the k2f cut out what makes it operate, mine has 2 copper strips an acorn nut with a small hole which I thought must connect to something thats missing, I have done as much remedial as possible to get it running but I have no idea what the engine is like so being able to stop it might be prudent if it starts at all that is
Dev

[Sakura]

Is your acorn nut hard plastic and screws into a lug on the side of the end cover? If so, you need an earth wire. Use a split copper washer under the acorn nut trapping a wire and take the other end to a cut out button. If you just want it for emergency use attach the end to earth via a switch.

[Greybeard]

.... being able to stop it might be prudent if it starts at all that is

I like your thinking there! 👍

[Devlin]

But what was the original device 🤔

[Triton Thrasher]

But what was the original device 🤔

A button somewhere that earthed the cutout wire to the frame.  The sensible place is on the handlebar, where you can reach it with your thumb.

[Swarfcut]

Devlin....see that screw in the middle of the points? The one that goes round and round in the centre? That's happily conducting the LT side of the maggy through the points. Joining this screw to the frame (and hence the magneto body) will earth the LT circuit and the sparks and motor will stop.

 How it's done depends on the version of magneto. Early types had a metal cover with a push button in the middle, a bit of a stretch to reach and steer the bike at the same time. Later types have a bakelite cover and a lead to a kill switch, thanks TT, simply running the current to earth. Finally magnetos had a screw on cap, but the principle of earthing a carbon brush bearing on the rotating screw remained the same.

 This is why trying a dead maggy without the cover eliminates any unintended earthing of the points.

 A simple piece of wire touching the frame  and then the rotating screw will stop it. No heroics, no big sparks, no bother. Just be careful.

 Swarfy.

[muskrat]

G'day Devlin.
All as above.
Funny I had that problem when I first started the A7 back in 81-82. It had the Early types had a metal cover with a push button in the middle but it still wouldn't stop The earth brush at the other end of the magy was buggered.
Cheers

[Devlin]

So a length of copper HT lead with a bare end will do as a emergency stop until I do a permanent switch
Dev

[Sakura]

Simply put - yes.

[Swarfcut]

 Sure will, but any old wire will do.  This is the low tension side of the magneto, not the High Tension Sparky and Powerful Part. Touch or connect your wire to the frame, then bring the bared end to the screw. With that circuit complete the points are no longer doing their job and the whole thing stops. Not for the purists but a short term dodge.

 Handlebar kill switch essential.....stuck throttle syndrome ain't too nice. Especially in the cold dark winter rain going down Gorsty Hill in Halesowen as happened to me. Managed to limp home riding on the kill swith and half throttle. Water in the throttle cable was the cause.

 Swarfy.

[Devlin]

I thought HT cable as it will stay in place since there's a acorn nut already fitted to the cover

[Devlin]

Although I still.cant see the physical connection from the carbon stub  and the metal strips

[Swarfcut]

 Devlin, From the description you already have a magneto  end cap. With an acorn nut fitting it is the bakelite clip on type. There should be a carbon brush (which bears on that central rotating screw) supported centrally in the cap by those metal strips with electrical connection to the emerging spigot in the centre of the acorn thread.  It does look like a connection for HT cable, but light duty wire will do fine. Plenty of pictures on the web. Connect as outlined above by Sakura.

 Later type cap screws onto the magneto, with a central nut and bolt wiring connection to the cut out switch.

 Swarfy.