Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Morgan 3 Wheeler Trouble Shooting HELP

In that long list you did not mention throttle position sensor...

Idle Air Control (IAC) valve sticky? Worth taking it out and cleaning it I reckon.
Also worth slipping out the Crank Position Sensor and cleaning / inspecting for damage too.
If Oxygen/Lambda sensors were faulty you would most likely get an error code.

Do those little rectifiers still fail, I remember quite a few owners of early 5 speeders having problems ?

These failures were more than likely down to poor earth connections although the Harley unit is said to be more robust

The H-D unit is FAR more robust. The stock rectifier, in the biker community, became known as 'delicate' or just a POS. It didn't really matter about the ground. My own replacement H-D rectifier, probably made in China, is still going strong.