Yes I know it's not a thumper.....
Dare I hope*....
... but I think I may have solved the Norton Electra starting problem. Some of you will recall that I've tried various things but never got the reliable starting (electric) that I want and expect. Finally I think I've seen the light. I've reassembled everything with all new mechanical parts, charged the batteriy(ies) up and gave it a try. The solenoid thunked in satisfactorily but the starter motor barely budged. What's more when I put a voltmeter across the battery it was dropping to 7 volts or so when trying to start.
So I left it on the naughty step overnight. The next morning, it was the work of but a few minutes to strip the primary chaincase and assorted mechanical parts and get the motor on the bench. Two screws had the innards out and ready for inspection a bit like Caesar's soothsayers. I discovered that one of the live brush leads (there are 2 live brushes and 2 earth) had worn through its insulating cover. This lead is next to the aluminium end cap which is supposed to have a fibre collar to obviate shorting out. This collar had been replaced at some time with PVC insulating tape and this had rucked up just where the brush lead was close to the end cap allowing contact. So what I deduce was happening was that the brush lead was shorting to earth on the end cap. What's more, I believe there's been a partial short there all along so reducing the available voltage from the battery. I would probably never have found this if it hadn't failed completely.
I made a new insulating collar out of a soft drink bottle and stuck it in with silicone, and wrapped the brush lead in PVC tape. A few minutes of reassembly and time to try it. Was I astonished when the engine burst into life at the first attempt? And even more that it ran for a few minutes, I could switch it off and restart instantly which it would never so before. And even left overnight it started first press of the button. I'm not yet confident enough to take it out on the road so had a celebratory lap of the local roads on the B'Zuki which is running very well.
This has been a real struggle. I've ended up replacing all the mechanical parts of the starter drive to give the whole thing a decent chance of working. I've also fitted a Wassell copy of the Amal Concentric Supreme carb although none of this made any difference before fixing the short. I'll keep the carb on as the original monobloc is fairly worn and parts for them are quite expensive - the new carb was only £112 and it's a nicely made bit of kit.
*as John Cleese once said (in the film Clockwork - the only time I've felt sympathetic towards him): “It's not the despair. I can take the despair. It's the hope I can't stand"
