Plus ça change.......

I understand the point you make. All is fine with the actual drive system which is now working perfectly. The hardened dowel pins I've used for the pivots - being reluctant to pay £45+ for the NOC items - are flush both ends and are a fairly tight fit in the holes. There isn't, as far as I can see, any longitudinal load on them so nothing top make them come out. The force required to fit them was similar to that fitting the 4mm pins in the pawls.

The current problem is not with the mechanics of the starter but in running.

I did have a colortune but gave it away years ago as I never found a use for it! I am however starting to form yet another theory - to wit that there's always been a partial short in the starter motor resulting in a very heavy drain from the battery, hence my attempts to provide a good supply to the Boyer unit. I have 2 plans of attack for tomorrow when hopefully it will be cooler:

1. Provide a direct feed to the white Boyer wire from my auxiliary battery without the relays etc which are currently controlling it and which of course introduce extra points of potential failure.

2. If this works, reverting to a Boyer feed from the main battery.

If neither of these is successful, trying plan 1 but with the original Mk3 Boyer ignition unit (after testing that I get a spark when switching off).

When the engine did start it was running well for a couple of minutes till it just stopped as if the ignition had been switched off, leading me to suspect the ignition circuit. But who knows?
 

... it helps! I take your point re battery capacity. In fact before I discovered the partial short in the motor the battery was starting to lose its oomph after a few starting attempts. Once that was rectified not only does the starter spin the engine faster, the battery also seems to provide plenty of power much longer. So I'm starting to think that there's been a partial short in the motor all along. If the motor is taking a lot more power from the batter via this short then of course what's available to the Boyer wil be reduced. But my auxiliary battery layout (see diagram below) should in theory (mine!) eliminate that as the Boyer is independently powered. But as I say that has introduced several new potential weak points hence my plan 1 above.

The current battery is indeed from Tayna who always deliver the next day even when ordered on a Sunday.  It's YB9-B AGM Powerline  Battery 12V 9Ah.

At least the constant search for problems and solutions keeps my mind active.......

... but just for the day! I am more than ever convinced that the root cause of all (well most of) my troubles was the partial short to earth on the starter brush lead. My current - see what I did there - hypothesis is that the short drained so much current from the battery that it depressed the voltage below what was needed for the Boyer. I suspect that this fault has progressively got worse.

In fact, I'd decided the battery was dying as it was starting to look weak after only a few attempts at starting. The always reliable Tayna provided a replacement but I now think that wasn't necessary.

The good news is that my refaced pawls and dowel pins are working well and when I had a look at them after a number of attempted starts the pawls showed no marking. Now if only I could get the primary chaincase oil tight again.

I'll have another look at the electrical setup tomorrow after leaving it on charge overnight.

again..... I have to confess I haven't managed to kickstart the Electra at all although I haven't tried it in earnest. It could be my technique although up till recently I had an ES2 with 8.5:1 compression which I could start very easily, and had Commandos for 30 years or so and never had a problem. However I am aware that at a couple of years shy of Eirik's age I'm neither as stron nor as well balanced as I once was. Although I'm not sure well balanced is a description some would apply to me.

Anyway, a fine morning so will pop out for a wander on the B'Zuki then return to the Electra later.

... and may well be why my kickstarting hasn't been a success. Unfortunately due to knee / hip replacements as well as general decrepitude - my principal reason for getting the Electra -  I need to set the kickstarter lower on its serrations that it perhaps should be, so achieving the two TDCs may be difficult.

Onwards and upwards!

... and why I rigged the auxiliary battery as shown above so the BB unit gets a full 12.7 or so volts. As a matter of interest, I've checked the main battery voltage when cranking. Even after several attempts, which previously would have seen it struggling, I'm getting almost 11 volts (previously 10.4 or so) which tends to reinforce my theory that there has always been a partial short from one of the brush leads in the motor, thus increasing massively the current drawn from the battery. Plus of course turning the engine slower than it should.

If I'd thought of this earlier I may have saved myself a lot of false starts (pun intended).

I now have it in a state where it will start and run most of the time although I haven't looked at the carb settings yet.

Well, I now seem to have achieved Electra nirvana (or close) in that I'm getting a reliable start, decent pickup and what's more restarting after leaving for a few minutes. Although I have yet to road test it....

My conclusion is that my original feeling that the BB box wasn't getting enough voltage / current was correct but that I misdiagnosed (several times) the reason. I'm now firmly of the opinion that it was down to the partial and later complete short of the live brush lead to the starter motor end cover. In fact, if it hadn't made complete contact I may still be scratching my head because as far as I was concerned there was no need to look inside the starter motor itself. The good news was that the commutator and brushes showed no signs of wear.

The brush lead has a woven sleeve which had frayed away on one side for about an inch next to the brush, exposing the braided copper core. The end cover should have a fibre sleeve inside it to act as a secondary insulation. This sleeve had been replaced in my motor by what looks like vinyl insulating tape. This had rucked up at one point next to the brush allowing progressive contact to earth. So a large proportion of the power from the battery was doing nothing more than warming up the starter. It was also turning the engine much more slowly than it should (and does now). I applied PVC insulating tape round the brush lead and made an insulating ring out of a soft drink bottle held in place with silicone RTV.

I will keep - at least for the time being - my auxiliary battery arrangement as well as the Wassell evolution carb - the latter as the monobloc the bike came with was well worn. I also haven't really wasted my time, or indeed much money, by getting the starter pawls resurfaced and fitting new pawl pivot and engagement pins, starter ratchet, sprocket and wavy washer as these were relatively cheap items. I do wonder whether the reduced speed of the starter and hence crankshaft contributed to the failure of the pins.

.... after a day or so rest. Not road tested yet but have every confidence now I seem to have found the root cause of the problem. I'll keep the wassell carb as the monobloc was well worn. The concentric will also allow the bike to tick over when on the prop stand which I've always found a bit problematic with monoblocs as the mixture weakens when they're leant over to the left.

... popped into the garage this morning and it started on the button. Third day on the trot, starting from cold (well as cold as it gets these days). Full air slide down, no tickling. I stopped it after a couple of minutes and retried it and again started immediately. Is that a light at the end of the tunnel?

... I would probably never have worked it out if the lead hadn't gone to a dead short. The engine turns over much more briskly now - hardly surprising as it isn't losing half its watts heating up the casing - and the previous slow speed can't have helped anything although not knowing what it should be didn't offer me any clues.

Hopefully will be popping out tomorrow for 20 miles or so and will take a couple of snaps. But I'll probably wait till I get home rather than risk a no-restart en route!