Have I got the right magneto ...

[Taid]

The bike is supposed to be 1957 and certainly the engine number begins 57/ ..

I read that the magneto should be a Lucas SR-1 but all the pictures I have found of the SR1 show it with a black 'plastic' end from the HT lead emerges .. but mine has a metal end and the HT lead comes from a different position

[ajscomboman]

Well in that case the answer is NO you haven't got the correct mag. Sounds like you have an N1 mag but only a picture can confirm what you have. The N1 is a manual advance retard mag whereas the SR is auto advance/retard.

[Taid]

Well in that case the answer is NO you haven't got the correct mag. Sounds like you have an N1 mag but only a picture can confirm what you have. The N1 is a manual advance retard mag whereas the SR is auto advance/retard.

I'll try to get a piccie sorted, .. I have no advance retard lever on the bars ...... just Brake , clutch, decompressor and choke .. at least, I think it's the choke ..

But no, .. it's nothing like the N1 .. it resembles the SR except that the cover plate is metal .. must get a photo tomorrow-ish

[Pharisee]

The auto advance SR1 magneto on my '55 M18s doesn't have a black plastic end cover either. The cover is pressed steel, with a passivated plating finish.

IMG_0585[1].jpg

IMG_0586[1].jpg

[Taid]

That looks like mine .. reason I was investigating is that I am wondering if there is any way to put an 'ignition switch' on it as a bit of anti-easy-theft security ..

The auto advance SR1 magneto on my '55 M18s doesn't have a black plastic end cover either. The cover is pressed steel, with a passivated plating finish.

IMG_0585[1].jpg

IMG_0586[1].jpg

[ajscomboman]

Well that is an SR but I've never seen end plates like that before. Maybe Groily will pop up and enlighten us. Another nugget of knowledge to add.

[SPRIDDLER]

I am wondering if there is any way to put an 'ignition switch' on it as a bit of anti-easy-theft security ..

Honestly, Ben, I wouldn't bother. It's very rare for a bike to be ridden away. My insurers told me that most are stolen by a couple of chaps in reflective jackets who turn up with a rented van with a stick-on sign: 'ACME Motorcycle Recovery' or some such fake name, chuck the bike in the back and are gone in two minutes. Insurance co's advise that it is chained, preferably to a post. You can always pull the plug cap off when you leave it in case anyone should try to start it.

[clive]

I have both metal and plastic end caps on my SR1s. The metal one I think is from a stationary engine.

[Taid]

Honestly, Ben, I wouldn't bother. It's very rare for a bike to be ridden away. My insurers told me that most are stolen by a couple of chaps in reflective jackets who turn up with a rented van with a stick-on sign: 'ACME Motorcycle Recovery' or some such fake name, chuck the bike in the back and are gone in two minutes. Insurance co's advise that it is chained, preferably to a post. You can always pull the plug cap off when you leave it in case anyone should try to start it.

Maybe I'm getting twitchy in my increasing years .. had the house broken into once, my cars broken into a few times and vandalised once and my caravan broken into plus another couple of thefts from my sheds .. no one ever brought to book .. but maybe you are right ..

[Groily]

There are quite a few SR1s with the tin plate end, but I'm not quite sure if they were for stationary engines or what. Seen a few on bikes, but that means nothing of course as they'll obviously go on.
In theory the metal end is nice; because the bakelite or replica plastic ones are so easily damaged round the holes for the screws.
In practice, I have found there can be very little clearance between the live side of the points wiring and the inside of the cover, and tin ones can therefore be prone to creating a short. Very important that the solder tags on the end of the wires from the condenser and from the coil are laid as neatly as possible under the cover, as far away from it as possible, and that the little nut and bolt that attaches them to the spring blade of the points isn't too long!
For a remote on/off switch Taid, you could always run a wire from the stud/nut on the side of the magneto, which may or may not have a bendy tag to stop the engine. That is 'live', hence all the insulation around it, so a switch on a lead to earth would do the job. Against casual joy-riders - but no use against proper thieves sadly!