Hopefully I'm not going to look too much like a complete buffoon by asking the following question!
I'm well into the rebuild of the maggy for my M20 and I've reached the point where I'm about to refit the fibre drive gear. I have a Lucas manual that goes into some detail about locking the dynamo drive and applying sufficient torque to the locking nut so that the 'clutch' mechanism will slip at a specified load to prevent damage to the gear teeth in the unlikely event (ahem!) of a misfire.
However... I don't have access to either the locking plug or the lever and spring gauge shown in the manual, so I wondered if there is an alternative method, perhaps using a torque wrench to apply a specific load to the locking nut with the drive gear locked with the 'bent nail' spragging tool? Or maybe there is another secret BSA methodology?!

Thanks in advance
Nigel

email (option): njgreen@bigpond.net.au

I looked at the shape of the end of the locking tool, which was a diamond shape, so got a bolt and ground it into a diamond shape. It works a treat.

email (option): horror@blueyonder.co.uk

I've just looked for the diagram of the tool I made but can't find it. I did find this picture in my Lucas Mag Dyno workshop manual.

email (option): horror@blueyonder.co.uk

Horror. I think what Nigel is asking, is how do you gauge how tight to do the nut up?

Ron

email (option): ronpier@talk21.com

The clutch should slip with a load of between 4-10 lb ft applied to the nut.