Hi all,Having tried two new electronic regulators and two rebuilt dynamos it still won't charge properly.With the lights on it's always discharge,sometimes 0.5 amp sometimes 4 amps.Sean at Hawker electrical suggested it could be the dynamo slip clutch. Has anyone had this problem? Any ideas gratefully received before i give up and fit acetylene lamps

Cheers Pat

I have had this problem, you can try to adjust the spring tension. Instructions are on the website

John

email (option): john.kater@chello.nl

I had this problem on my B33 for some years until I got round to fixing it, sometimes it would be ok then the dynamo clutch would slip and not charge with the lights on.You need to remove the mag dyno unit take of the triangler plate, inside you will see a large fibre wheel with a large fingered washer bearing on a steel ring this is the clutch, now knock back the locking washer on the centre nut,lock the gears, I use a mag gear then fit a socket to the nut and using a touque wrench apply 20 foot pounds the clutch should hold this without slipping if it slips tighten the nut. BSA recommend a one foot bar and hang a 20 pound weight on it, use what ever you have to hand.

Just hunted through tech section for slip clutch setting instructions ??? cryptically concealed? What's it listed under?

Cheers Pat

Sorry Pat, it might be hard to find. It is under TECHNICAL INFO and then: maintenance manual. You have to download.

John

email (option): john.kater@chello.nl

I see that the manual instructs one following assembly to: "Refit the dynamo and pack the gears with high melting point grease."
Does anyone do this? Use the grease on the fibre washer I mean.

email (option): brucekirby@telkomsa.net

So what exactly is this slip clutch for, can anyone tell me? I understood it to be incase of backfire but I cant see how such would do any damage to the dynamo.

john kater

Sorry Pat, it might be hard to find. It is under TECHNICAL INFO and then: maintenance manual. You have to download.

John

email (option): viaconsu # planet dot nl

L.J. - from the manual described earlier:
"A shock absorbing drive is incorporated in the larger of the two gears, which take the drive from the magneto shaft to the dynamo. This considerably relieves the peak loading on the teeth of the driving gear and gives a far longer life. The drive is taken from the gear centre (A), which is keyed to the magneto shaft, through the fabric gear (B), which is
held against the gear centre under the pressure of the star shaped spring (D) to the pinion (G) on the dynamo shaft. The effect of a violent overload is to cause the fabric gear to slip relative to the gear centre and so prevents shock from being transmitted to the fabric gear."

email (option): brucekirby@telkomsa.net

[/quote]

You mean the 8 page 1966 BSA Service Sheet No. 802? [/quote]

It is even better Hans, this manual has 49 pages in PDF and is a 2.6 Mb download

John

email (option): john.kater@chello.nl

I tracked down BSA and Lucas service sheet on the net.I still don't know if the slip clutch should be greased(you would think not).The friction face's of the fibre gear are badly pitted/worn as is the friction washer.
Cheers Pat

Hi Pat, I had problems with my dynamo drive a few years back,I have cured it and it now works as it should, the advice that I list below was given to me by an ex BSA employee and it has worked for me!!

you will need to buy and fit a replacement metal slip ring, and spring metal clutch spider, when you tighten the centre clutch nut ignore the BSA torque figure, and tighten until the nut will go no further (do not go beyond this point) finally you should grease the drive gear unit, use high melting point grease and apply the grease after you have finished rebuilding the dynamo drive (not to much apply around the edge of the fibre drive gear). I followed these instructions and my 1942 WDM20 has not had any charging problems in the last 10 years. Hope this helps you. Peter

email (option): petersmith542003@yahoo.com