I expect that you all know this, but oven cleaner really does work wonders on fouled plugs. I just could not get the Augusta to run properly under load and kept stripping and rebuilding the Weber carb that is fitted - about which I could find no info. The plugs were new, the coil was new and the points were perfect. I just happened to be discussing the problem with Mr Green of the Green spark plug co who explained that modern petrol with modern plugs in old low compression engines is not a good combination. Apparently, spark plug manufactures stopped glazing the insulator noses in modern plugs because modern computer controlled injection systems do not flood engines. Of course, I had been experimenting with the enrichment(starter) device which would have wetted the plugs on various occasions. He recommended trying oven cleaner which I did and - wonder of wonders - she runs beautifully now.