The Marston Sunbeam Club & Register Forum

General Category => Technical Discussion Forum => Topic started by: Ian Roberts on July 14, 2024, 05:22:27 PM

Title: 1932 Model 9a - Removal of Magneto from Platform
Post by: Ian Roberts on July 14, 2024, 05:22:27 PM
Hello
I have done a search, but could not find the info.

My magneto is fixed to the platform by diagonal opposite square nuts.
The timing cover side, the square nut is to the rear of bike.
The primary drive case side, the square nut is to the front of the bike.

The other two holes of the magneto platform seem to have plain stud fixings screwed to magneto base.

My question is regarding the primary drive case side - I believe Sunbeam provided a spanner in the tool kit for the specific use to remove magneto fixings nuts.

No spanner I have can access the space between the top of case and under magneto platform - so I have decided to make one.

Does anyone know the size of the square nuts that hold the magneto to its platform (if these are original or a replacement).


Regards Ian Roberts
Title: Re: 1932 Model 9a - Removal of Magneto from Platform
Post by: Rick Parkington on July 15, 2024, 07:12:12 PM
Hi Ian, my '32 9A was pretty original as bought and had 5/16 W size hex nuts on studs in the opposite corners which were a complete pain to reach. Can't remember exactly now but I think I replaced left side one with an Allen socket head bolt for which I used a cut down key  - but they were certainly not square headed on my bike - I think Ariel used square headed, flanged bolts on older models though - so someone has done like me and put something more accessible in.
Cheers Rick 
Title: Re: 1932 Model 9a - Removal of Magneto from Platform
Post by: Ian Roberts on July 16, 2024, 08:35:02 AM
Hi Rick

Thanks for your reply.
When I eventually remove magneto (today I hope) I will take your advise and fit Allen key bolts.

Cheers Ian
Title: Re: 1932 Model 9a - Removal of Magneto from Platform
Post by: Thomas on July 16, 2024, 08:40:11 AM
Hi together, my 1937 Model 9 has regular hex bolts and I can reach them with a regular ring spanner. It's a bit tricky along the primary case, indeed, but it works.
Cheers, Thomas