[Exstress]

Thanks Vic, I have a 1956 S7 deluxe which I had to polarize recently.  Presumably its the same method?  I live in Cheshire so its a bit too far for you to pop up and help..... but thanks for the offer, much appreciated.
I had to put an electronic replacement on the S7dl when the regulator started blowing bulbs.  I got 2 by mistake so hopefully the spare one will work ok but I'm not sure without looking if the S7dl is 6v positive earth, in which case it wont be suitable for a negative earth system.
J

[VicYouel]

Looks like a postwar dynamo with a bakelite cover so will be two brush. It may well need polarising to make sure that in the direction it is rotating it is producing the right polarity. Best to get this all ok before you try and connect a regulator because it can all cause damage to the dynamo field coil if wrongly connected. 

I usually remove them from the bike and connect them to a battery first and "motor" them to ascertain polarity and rotation direction.

As for wiring it is all pretty logical but it sounds to me that quite a lot of studying of literature is necessary or get someone local to coach you.... if you are not far  from Bracknell I am happy to help

[Exstress]

Thank you to everyone for the very informative replies. Vic, photo as requested.

John.

[Greybeard]

Hello.
It is possible to get 12v output from a 6v dynamo though it will generally mean that if you run the engine slowly or with lights permanently on it may not generate enough power to charge the battery properly. Running on 12v also gives you access to cheaper, more readily available bulbs or LEDs which are great if you do a lot of night riding or want to use lights during the day.
I was a total numpty when it came to the black art of electricity  although I'm quite happy to repair or make anything I can actually see working. If you haven't already got a copy I would strongly recommend this book -
https://www.amazon.co.uk/Classic-Motorcycle-Electrics-Manual-James/dp/1847979955
It goes right back to basics and explains it all very clearly and with excellent illustrations - it even has a piccy of a Sunbeam on the cover 
For a modern regulator, these folk are well regarded and an excellent company to deal with. I've recently bought their belt-drive conversion for my Golden Flash. Superbly made and runs silently (the belt drive that is)
http://www.dynamoregulators.com/dvr2.php
With regards to additives, I only use one as a fuel stabiliser. I tend to keep a couple of jerry cans of fuel on standby that gets used over a season in the motorbikes, outboard engines and the lawnmower. Millers VSP is the one I use. I don't think it's really necessary to protect the valve seats - my 60 year old Rover has run happily on the green stuff for years now with no sign of valve seat recession. I dare say if I used petrol more quickly in every bike keeping the fuel fresh wouldn't matter so much   

Steve

[phutton]

If you want to fit an electronic regulator, you may need to modify the dynamo slightly, but the regulator will come with instructions. You then wire the machine as if it was a 1950s Lucas system.

P.

[VicYouel]

Welcome to the world of Sunbeams; I removed your earlier post under the other heading.
Any chance you could post a picture of your magdyno? A Bakelite end might be on the dynamo
System like most would be 6 volt negative earth and possibly a type MCR1 regulator but depends what sort of headlamp and swich are  fitted as some have a half charge position and integral wire wound resistor.

You can update for a modern regulator
I don't bother with a petrol additive but add a little two stroke oil
Good luck
Vic
PS Wiring is pretty logical and easy to work out

[Exstress]

Hello, thanks for letting me join.

I have recently purchased a 1935 Model 8 twinport.  The bike is 80% complete and I have just started to work through the remaining jobs.
There is no wiring whatsoever but the Magdyno has allegedly been reconditioned.  The Magneto has a Bakelite end and I believe this model would have had a voltage regulator?
Could someone answer the following queries please.
1, Was the bike 12v or 6v?
2, Positive or negative earth?
3, If the regulator is required would a modern electronic version be better?
4, I have the wiring diagram in the "Book of the Sunbeam" but this does not show any regulator wiring.  Is there a
   wiring diagram available?
5, Will a petrol additive be required?

Any information will be appreciated.

Regards,