Still having carb problems, and attendent lack of power, and have learned how to service the carb. Discovered that the screw holding the pivot arm in the carb was stripped, and loosening up – it was a US size – 40 something – so I tapped the hole with a 3mm tap, and used a 3mm screw, and that is fixed now.
I found this document on EC’s website, that I think is very valuable. Thought I would share it. If you page, has information on HL carb blueprinting as well.