After getting the engine out of the frame, decided to swap in the new engine, after re-rigging a new stator and rotor and matching up the connections to the ignition coil.
Engine in and also went back to one of the original exhausts, as the mounts had broken on the Circle F I had. Made up a new bracket for the rear using great meccano strip metal which I’d found near Abergavenny station (not off the track) whilst trying to fix the Polo exhaust.
After that, decided to strip the original engine and see why the selector was stuck. Removing the clutch side and selector mechanism, demonstrated that the drum was indeed still stuck. Oh well, time to split the cases.
Doesn’t take long to split the cases, (with the soundtrack was Saint Etienne and The Seahorses) and the problem was revealed, with some pieces of metal lying underneath the selector drum.
Removing the metal, it look like the inner race of bearing, but a check of the the cases and all the bearings were intact. Strange. Time to call Mr Holmes. Cleaned out the cases and continued to search.. Hmm, no problems.
Going to the Parts book and searching through the Transmission diagram didn’t turn up anything and check, all the bits that were meant to there, were there. But checking the balancer shaft diagram, which had been removed from the engine, showed a bearing with a detached inner face. Probably root cause, which hadn’t damaged the gears, but broken up and ended up in the bottom of the case.
Further work to be done, but the cases are back together, with clutch side and top end to be rebuilt.