Morris Minor Owners Club

A quick follow up:

I removed the rocker cover and cleaned out all the mayonnaise
I removed the breather expansion tank to find that it was completely blocked. It was difficult to reassure myself that I had got all the muck out so I cut it in half and installed a s/s scouring pad as suggested. I did consider replacing the top with a silicon reduction hose but decided that it was too close to the exhaust manifold. I have re-assembled the tank The breather hose still goes to the air filter there being nowhere else for it to go. There it will stay unless an affordable opportunity comes my way.

I have now got the water temp gauge powered from the voltage stabilizer on the back of the speedo so 10v. Finding the screws that release the speedo was no fun with the glove box liners still in place. The temp gauge is now reading much less, around 80 degrees rather than over 110 previously.

Next step, a bit of radiator blanking and a long run with some serious traffic.

Thanks all for your advice. all very helpful!