So this week, I've been out and about for another short ride, but first I refitted the Morgo pump. I did about 8 miles as usual, out of town and up to 40 mph. The lubrication job I did on the speedo seems to have stopped it sticking at full range.
The Morgo obviously provides more oil flow than the plunger pump, and I finished the journey with about 10 psi on the oil pressure gauge.
I also finished the journey with a completely flat rear tyre, which looks like it might be a valve failure. I wobbled along the road, complaining about the tramlines the council left when they resurfaced, only to keep my wobble, rapidly turning into a squirm from the rear end, when I ran out of tramlines. I recovered the puncture with a handy can of tyre weld I had in the pannier.
Of course, the low oil pressure problem is not sufficiently improved with the Morgo to use the bike in anger. Lifting the rocker covers with the engine running (rather dangerous - they are very hot) you can see little jets of oil coming from the rocker oil holes. I've fitted three new old stock rocker shafts to deal with the wear I found in the shafts last year - one was already fitted due to a damaged thread:
A thought occurred to me, corroborated by AOMCC forum members - retarded ignition causes overheating. Checking accurately revealed that the ignition was indeed retarded: I moved the distributor about 10 degrees, equating to about 20 degrees at the crankshaft, to get it right (thanks MikeN!).
So we will have to see what happens. Just waiting for a new inner tube...