AJS & Matchless Owners Club

I am thinking of adding an anti-sumping tap to my '54 G80 but it must have a magneto cut-out to avoid disaster. Where is the connection point on the SR1 for a wire to a cut-out switch?

There is a stud about half way up, on the right hand side usually, as you look at it from the contact breaker end. It might or might not already carry a tab that you press to stop the engine, or you might be using a decompressor for that.
Inside, the low tension live wire from the coil to the contact breaker is attached to it, and the stud is insulated where it passes through the casting. Shorting it to earth is what stops the sparks.

Thanks Groily

I took off the aluminium tab with the green printing on it and put a cut out button on the handlebars (like a horn button but red. I prefer it to using the valve lifter.

Getting at the screw can be difficult as the back of my SR1 is close to the barrel.

JohnnyB

I think you are wise on both points JohnnyB. The tab is a poor bit of kit and not easy to get at on a bike, although no doubt just the job on stationary engines. And if I had a single I'd prefer to kill the sparks than use the valve lifter. Button on 'bars has to be better and also probably safer for being easier and quicker to operate in the event of disaster. On a couple of mine I use on/off switches in fact, for that reason.

Spot on about disaster. With the Matchless on top of my leg and still running, it was easy to press red button.

JohnnyB