Andy,
I would agree that a 2A is a very simple engine to work on. Where we will diverge hugely is that because the flywheel was all but welded onto the crankshaft, it was a devil of a job to get it off. Your method would have failed in the first instance. Persisting in it would have damaged or broken associated parts.
Attached are more images of the state of the shaft and the puller method I used, complicated you may say, but a necessity if the seized flywheel was to be pulled off the shaft. It consists of two pullers, one with the 4 hole attachment that I could fit the 3 whitworth bolts into. The bolts ideally needed to be longer, but this is all I could get hold off on a Saturday morning. Because the side hammer element would not fit as the crankshaft was too close to the centre hole. I got another puller to go on the attachment and placed 2 nuts in the middle hole to act as a centring spacer. It involved a 1/8 turn of the puller hex end, followed by several sharp blows on that end, for another 1/8 turn to be done and more blows. Repeating the process many times until it was free. You may describe it as complicated, I believe that I used care, skill, experience and a range of tools, applying them all in unison to do a difficult job.
Again you may say my ignition testing technique that I have shown in the imagery is complicated. I would contend that it is a simple and quick diagnostic method of establishing where a magneto ignition trouble lay. In this case it was a 74 year old condenser with a wax paper dielectric, the primary and secondary coil windings are fine. Sending the ignition parts away to be tested, or just using the substitution method would have resulted in additional time and unnecessary expense in fixing the problem. FYI, testing took 4 minutes, the cost of the polyester film capacitor and board to mount it on is 45p, estimated time, 15 minutes.
You may say too that my intended fitting of an external coil is complex too. To my mind it is not, however I do concede a rudimentary understanding of mutual induction is required. Am not doing it to fix a failed coil, but to do an experiment to see if firstly, it actually works and secondly, if it does, is it better than a known good original system. I want to find out if winding a primary in my own workshop on a homemade jig and fitting an external coil is worth doing as opposed to purchasing an expensive new one. I could then advise others with greater confidence, as I would have completed the conversion myself. I also get great enjoyment and satisfaction from doing such projects.
Grahame
