1936 Model 9 Magneto Change

Started by Empire.Services1, August 10, 2020, 10:38:20 PM

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Thomas

Yes, Paul, that's right. A bit tricky but it works.
1946 BSA C11
1937 Sunbeam Model 9
... and a scratched Hyundai
(MSCR member)

phutton

Sorry Thomas, I think I may have mis-interpreted the photo. Do the nuts go behind the chain at the top of the sprocket, and behind the sprocket at the opposite side?

P.

Thomas

Hi Paul!
QuoteI certainly wouldn't advise using a puller such as you have made. The back section of the magneto case is notoriously weak, and prone to cracking.
My puller doesn't touch the back section at all. And it's basically for free.  :)
1946 BSA C11
1937 Sunbeam Model 9
... and a scratched Hyundai
(MSCR member)

singleminded

A dob of grease on the pump swash plate greatly assists with getting the cover back in place.

Empire.Services1

Hello Mark,
Thanks for the reply & support. Well i ordered the puller from the club, my thanks to Graham, & Vic for the excellent service. Well i manged to get the Magneto out. No real problems i wanted to leave the timing case in place but as you have to lift the magneto up and the timing chain gear is in the way the best way forward was to just remove the cover.

MarkO

Hello

I have just been through the same exercise with my model 95L - even to the extent of modifying a cheap spanner to get at the nuts under the platform. How difficult could they make it?
One thing I discovered is that the threaded counterbore in the magneto pinion shares the same thread as the clutch stop adjusters. I utilised the clutch stop adjuster by unscrewing it from the primary drive outer cover, removing the friction material and then, with the help of an M5 nut to act as a spacer, I screwed it into the magneto pinion reasonably tightly to load it up and then gave it a sharp tap with a copper mallet. The pinion popped off easily. I could have ordered a puller and waited, but being the impatient type...
It is obviously important to make sure that the spacer is thick enough to stop the clutch stop adjuster screwing  fully home into the counterbore - otherwise this wizard wheeze will not work. Of course if the pulley is really tight on its taper, it may not work.

It always amazes me just how much of a kerfuffle it is to time up most british bikes! - I still love them though!

I does mean that you will need to reset your clutch stop afterwards of course.

Rgds

Mark

Empire.Services1

Good Evening All,
I would like to thank you for all your feedback. I have been asked to document and provide photo's on how I am getting on with the task to remove the magneto and get it overhauled and then refit it. One of the key tasks i have been asked is to go through is the ignition timing. Again i am more than happy to chart my progress. I have below outlined the key tasks i have undertaken to date and a couple of questions if i may.
1. Turned the engine over on compression stroke [I checked by making sure both valves were closed at TDC]
2. Removed the Primary Cover to be able to turn the engine over and also to be able to attach the timing disc for the ignition timing.
3. I manged to get a cheap spanner and bend it at an angle, to gain access to the two nuts. I also milled down the jaws of the spanner to help [5/8 AF]
4. I also ordered the special tool for removing the pinion.

My next task is to remove the nut to gain access to the pinion and the timing gear. My question: Is the nut on the timing gear on the magneto anti - clockwise or clockwise to remove.

Anyhow any advice or corrections, please feel free to comment. I have posted one of the photo's but i have others if anybody would like to see these, happy to send direct.

Thanks again
Steve

phutton

Hi Thomas,

I certainly wouldn't advise using a puller such as you have made. The back section of the magneto case is notoriously weak, and prone to cracking. Having said that, you look to have got away with it! Klaudius's design is the same as the one the Club sells.

Paul

klaudius

#8
I also have a self-made puller. Works like the original with pressure screw from the inside.
It is built from the remnants, the thread coincidentally fitted with the ring gear of the magnet.
Greetings from Germany .

Thomas

A low cost selfmade mag puller.
1946 BSA C11
1937 Sunbeam Model 9
... and a scratched Hyundai
(MSCR member)

klaudius


Good Morning
I would have advised you to only commission the winding and do the rest yourself. That's what I did and it's a lot of fun to bring the old technology back to life. What kind of magnet is that? Mine was an MS1 ​​1932. All parts are still new. You should only watch out for the bearings. Either use the old balls with new ones or, as I do, completely renew them. The bearings with one another are not combined with their raceway shells. Please excuse my english. Greetings Klaudius

Empire.Services1

Hi Graham,
Thanks for the reply, more than happy to take photo's etc. I did go out and take a look tonight and i must admit you were correct about the nuts being fiddly to get out!
Again my thanks
Steve

shorrog

Removing the magneto is fairly straightforward but you will need an extractor to remove the sprocket. If you don't have one the club sells them https://marston-sunbeam.org/sunbeam_shop17/tools/329-mag-pinion-extractor.html
So you remove the timing chain cover then the nut holding the sprocket on, use the extractor to remove the sprocket.
Then the fiddly nuts holding the magneto to the mounting plate.


If you go ahead would you mind taking some photos and posting to the forum as this question comes up fairly frequently.
Graham

Empire.Services1

Hi Graham,
Many thanks for your reply, I am over the moon with the Model 9. I am not a restorer, but I do have some engineering skills. I try and do all the work myself. As I am new to Sunbeams I was looking for a manual or any guidance in removing the magneto. I do have a copy of the Pittman Sunbeam manual but I was looking for more details.  I use D.H Day for any overhaul of the magnetos. Many thanks for getting in touch. I live in the Scottish Borders and I find forums like this very useful.
Thanks again Steve

shorrog

Hi Steve, firstly welcome to the forum and congratulations on your new acquisition.


I am not sure of your expertise but I do know that overhauling a magneto completely is a highly specialized job and there are very few folks that can do it. If the magneto has been unused for some time it may well require a rewind plus replacement of brush and contact points. The book "The Vintage Motorcyclist Workshop" by Radco has a good section on Magnetos and gives quite a bit of detail on how to inspect them.


If you are looking for a professional restorer then quite a few folks in the club (me included) have used Tony Cooper from Halesowen his details are on the suppliers page on the club website.


Graham

Empire.Services1

Good Evening,
I am new to Sunbeams, and have just purchased a model 9. There is a problem with the Magneto which will need to be overhauled. As I am new to this make is their a workshop manual that I can follow or anything I should look out for?. Any help would be gratefully received.
Thanks all
Steve