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[richy]

Help Please,
I am just rewiring an early Redditch Bullet fitted with a Lucas MOIL Magdyno. There is a terminal screw LU/467518 fitted just below the contact breaker cover. Does anybody know where the wire that this screw secures goes to. It is not shown on the wiring diagram I have. Thank you in anticipation. Richy.

[Dennis C]

The M01 as with other Lucas Magneto's had quite a few variation's, the connector you describe was only fitted on some, a picture would help but it is almost certainly the stop button connector, this is a simple button just like the horn button and connects the lead to ground when pressed effectively shorting the points to stop the spark being generated.

[richy]

Thank very much Dennis. I just thought you pulled the decompressor lever when you wanted to stop but I'm sure you're right. Thanks again.

[Mark M]

I have to disagree with Dennis here, sorry! I have this terminal on my 1953 500 Bullet with the same Magdyno. I think it is an additional earth for the dynamo, at least that's what I have wired it up to do! The earth for the dynamo is, as standard, just through the clamping action of the dynamo case to the mag body then through that to the engine and then via the engine/frame studs to the rest of the bike, all a bit tenuous really! Mine works fine wired up through the terminal but I assisted a pal to build a 1955 500 Bullet with the same set up and unknown to me he painted the dynamo body silver (as a money saving measure, they were originally cadmium plated,) which acted as a perfect insulator and his battery wouldn't charge,which I think proves it!

REgards, Mark

[richy]

Thanks Mark,
The plot thickens.
Richard

[Dennis C]

It's not hard to check, if it is an earth it will be mounted straight onto the body of the mag, if to a stop button it will be insulated and wired internally to the points, let us know what you find please, the variation in all Lucas mag's beggars belief sometimes.

[Dennis C]

I think that Mark is correct re it being an additional earth connector, having re read your post the connector would be on the end cover not underneath if it was for a stop button.

[richy]

Thanks to you both. I'm going to go with the additional earth fixing as it is definitely not fitted to the points cap and is not insulated from the Mag body.although the body of the Mag seems to be earthed just fine without it but I guess one more earth won't do any harm. Thanks again.

[richy]

ThePlot thickens. The experts at our Hosts think it is for a stop button.

[Dennis C]

Hi richy, any chance of a clear picture, if not is the connector insulated from the case or just connected to it?.

If it is insulated then it could be a stop button but I can't see how it would connect to the rotating points, the stop button is normally fixed to the end cap and has a carbon brush which runs on the centre points mounting bolt.