thanks for all the comments - yes I have been adding castrol valvemaster or whatever it is called. It has original valve seats so I thought it might be a good move, perhaps not! The super unleaded I guess is a good idea. Regarding the carb set-up I did go through the Amal procedure, although lost patience a bit after several changes and not being totally sure if it was getting better or worse. Installed a new throttle slide as well although needed quite a bit of rubbing down to get it to fit which could mean the carb body is a bit out of shape. The other thing is it has boyer electronic ignition and without any timing marks to go by for a strobe gun, I did the timing by feel as it were. With so many variables I guess it could easily be off somewhere. Having said all that it was running quite well. I guess not too much to worry about except perhaps some tweaks when I clean it up and get it back together. I guess checking the colour of the plugs might help, come to think of it I have a colour tune gizzmo in the shed somewhere which could be worth a try. Again thanks for the comments, seems to be some concensus that it is sootier than it should be.
