This is pretty lengthy, my family sold Bsa motorcycles and I went to Bsa service school in 1970-71 The last Bsa service school of course. Well I 1966 the industry shifted from 6v-12v There is a serious problem with the bikes blowing up and seizing up and running terribly poorly, in their infinite wisdom they forgot to change the ignition cam to compensate for the 12 V System. 6v ignition cam add 220° of dwell, 12v oh I needed 180° of dwell, this manifested itself into maverick spark was a term they used. This means the ignition system Would fire the plugs at any time it felt like it. For instance you're sitting at a light idling and for no apparent reason the engine would stop.As for plugs were firing so far out of time it was trying to make the motor run backwards. It took six months for Bsa to get new ignition cams it drove us crazy . Dealership on the West Coast put a bike on an oscilloscope and discovered the Maverick spark. Jerry Brown (? A higher up at BSA trying to remember) Flue to Nutley New Jersey east coast supplier for Bsa test rode a bike for a week, mostly wide open, and said that we were all crazy there's nothing wrong, The maverick spark always showed up at low RPMs, if you rode the bikes hard ignition timing would work properly. Customer in 1995 found in A65/66 model lightning we're still had the 6v Ignition Cam in it. He had spent $8000 on the restoration I cannot figure out why it was running so badly. His bike was beautifully restored. I installed Boyer electronic ignition and that fixed his bikeHope this helps someone.

Funny I just assembled a Bantam from Ebay bits, it started easily but like yours revving way too high. Then I realised I had wired up the ignition with no way to stop it! I had to wip the spark plug cap off. Plus I have the same random bolts issue, BSF, UNC. BSW, metric!!

The timing plug flat is uppermost for the A 50 and facing down for the A65 according to the BSA workshop book

You'll only need 3 adjustable spanners, a metric, imperial and whitworth one for that lot, lol. Nice video, and well made, subscribed.

great to see something again your cb400f videos helped me out alot with mine last winter really well made informative on the little details

Great video. There is a bolt in the kit that screws into centre hole of the advance/retard unit. Screw it in and it takes the unit off it's taper complete.

How could you tell the bolt needed to be shorter....was there play in the rotor after you tightened the bolt? I put mine on earlier today and it feels pretty secure and tight.

I fitted a TriSpark electronic ignition. End of problems. The A65 isn’t a difficult bike to get running weel, unless it’s f@cked.

Zener Diode ok? rectifyer ok? Condesor ok? Coils grounded properly?