1960 24TCS Scottish, one of the two barn finds

[garybam4711]

The Bosch name will probably be on the rear off the stator plate

[John Wakefield]

Right I now have the info. The flywheel mag is a Bosch from a snowmobile, a 12 volt system, the outer flywheel was made by Metal Profiles and then fitted to the Bosch flywheel
The man to contact is Clive Tompkinson he was the person who designed the system when at DMW (Ian its OK to ring him, his number is 07970 442412)
Clive says its a brilliant system but be careful not to damage the advance and retard mechanism, also DO NOT separate the inner flywheel from the outer as it will upset the balance.
Apparently quite a few engines were built with this system and many got sold off in the DMW liquidation, so thats probably how it came to be fitted to a Greeves. It would have originally had the DMW square alloy barrel.

[IanCordes]

Well done John, thanks for that. The a/r systems seems sound, working freely. The points look pretty new, surprisingly, but it would be good to cross-reference them to know what the replacements would be, for future reference. I will contact Clive Tompkinson. Sounds as though he would know.

Handy too that it is 12v. That will tempt me to rig lights up on it in due course. I must pick Tony's brains on that one, as he has his finger on the pulse of correct lights for the period.

I will rebuild the engine as it came, with the V.O. barrel and Hogan (?) head, as it is part of the bike's history now. I have looked for timing marks, but nothing obvious, so I will scribe marks on the stator plate and inner timing cover before separating them; assuming the timing is set correctly, that is. No big deal to re-set it, having remembered to wedge the a/r unit fully advanced first.

Sounds as though you have come across this system too, Gary?

Cheers
Ian

[justalad]

Hi
I haven't read all the posts on this thread but I presume you are asking what you have in post #12

Yes, it is a Bosch flywheel magneto.

These were adapted and sold by DMW (the original DMW in Dudley)
to fit the 9E type motors as a replacement for the Villiers magneto
in the 80's and 90's, when DMW were selling Villiers spares.
From DMW it came with it's own inner and outer cases.
The one in the photos has been modified to fit inside Villiers cases and an
extra ring has been added to the periphery of the rotor for additional flywheel effect.

As standard there is not enough flywheel effect for trials so I too added a steel ring
on the rotor periphery and a leaded ring on the outer face of the rotor. Then worked the whole magneto
inside Villiers cases. The engine now plonks nearly as well as the Villiers trials flywheel.
The set up works well, just turning the rotor by hand produces a bright blue spark
and has the advantage of some mechanical advance.

Not sure about Clive Tompkinson's involvement in the design, think these were about before Clive got involved.
He may well have fitted some to Villiers engines when the DMW system was available.
His version of the Villiers ignition system was the 'Little Demon' (in latter years anyway).
But I might be wrong of course.

[IanCordes]

Hi Justalad!

Thank you for the additional info. It does seem well engineered, and the auto A/R must be beneficial. I had to get a local engineering shop to make me up a flywheel puller, but it is all apart now.

The engine is at the point where it can now be rebuilt. It is a bit of a mixture, because the Vale Onslow barrel and (Hogan?) head seem more scrambles orientated than trials. It was fitted with a 26mm Concentric on an inlet spacer with a 29.5mm bore. I will have to try it and see.

Do you know what points are used, if ever I need to replace them?

One wonders why DMW felt the need to replace the Villiers magneto as an after-market item, as it needed quite a bit of modification to make it suitable for trials work. The Villiers one worked well enough, particularly with the cheap modification of a Japanese coil under the tank, which my set-up also has.

Cheers

Ian

[John Wakefield]

One wonders why DMW felt the need to replace the Villiers magneto as an after-market item, as it needed quite a bit of modification to make it suitable for trials work. The Villiers one worked well enough, particularly with the cheap modification of a Japanese coil under the tank, which my set-up also has.
Ian

Presumably as the original Villiers ignition system was no longer available after Villiers stopped selling engines to other manufactures. DMW made their own crankcase/chaincase castings, barrel & cylinder heads but would have needed an ignition system, so presumably found the Bosch system available that could be adapted

[John Wakefield]

Are you sure Ian they look like Bosch Puch Maxi ones to me http://www.50cc.eu/en/product.asp?P=...bosch-replica#

[IanCordes]

Could well be, John. I was looking at the wrong set on the bench! As it happens I don't think they need replacing, but perhaps Justalad can confirm what they are?

[John Wakefield]

They are only £6.28 from Motorcycle Products https://www.motorcycleproducts.co.uk...SABEgKMMfD_BwE
I have used this company for Yamaha Townmate parts and recomend them good prices and services
Worth buying a spare set!

[IanCordes]

It is similar John, but not the same. Look at the top screw on mine; there is no provision for that on the Puch one. I have just searched for Bosch contact breakers and found this site, which appears to have the correct one. See what you think....http://www.mopedland.co.uk/electro/

[John Wakefield]

Looks the same to me, so obviously from a moped set up. Mark Daniels of Mopedland looks your man

[IanCordes]

A question for Justalad really. As I mentioned previously, there are no obvious timing marks. Presumably you set as usual to 9/64th btdc, but what do you do about the a/r setup? Jam it in the fully advanced position?

Thanks

Ian

[teamferret]

My advice is to get it running and use a strobe to check it's correct

[justalad]

Ian
Can't help with points, from DMW they came in a yellow Bosch blister pack.
You seem to have found an acceptable alternative.
However, just look after the ones you have and they should last indefinitely nowadays.
Lubricate the cam and heel and keep the points clean and oxide free.
Timing, just set static at about 3mm BTDC with the cam at full retard (where it is, or should be spring loaded to).
Then run the bike, experiment, and see what you are most comfortable with and adjust the timing accordingly.
It's not an exact science because modern petrol is very different to the 4 and 5 star of the 60s and 70s.
I find that engines generally require more advance now to produce power than decades ago.

Now, someone's going come along and say I have got it all wrong. But that's what I find anyway.
Regards
The Lad

[IanCordes]

Thanks gents. I marked the stator before removing it, and it is now refitted, having fitted new main bearings, oil seals etc. Drive side is assembled, so when the barrel goes on I will check the timing then.

Cheers.
Ian