Well, I have been messing around with the mixture screw and that has only managed to make things worse. It is running very rough now at full throttle. Maybe I should use some RTV silicone around the manifold and tank gaskets - rule out any air leaks. The air vane mechanical governer and loose linkages are rubbish IMHO. Do you think the cold weather has any effect?
BTW, I have gone ahead and purchased the digital tachometer from the link you posted, should be here sometime soon.
