I have just checked the needle groove position on the carburettor as I was suspicious that the bike was running too lean. ( 1956 Dominator 99 ) due to the very light colour of the plugs and difficulty re starting from hot. The needle should be in the third groove from the top but was in fact in the first groove !
The needle is letter 'C'. What is the standard letter code for the needle for the Monobloc ? I have not checked the pilot and main jet numbers. Nor as yet checked the fuel level.
The strange thing is that prior to a couple of weeks ago the plugs were sooty indicating that the bike was running too rich and restarted from hot without a problem. The change seemed to have taken effect during it's running in period of which I have done 360 miles so far all with the needle in the incorrect position. I am beginning to doubt my sanity.
Perhaps the sooty plugs was oil ,and now its more run in the oil is not being burnt.
From a Phil Hannam post. See attached!
I have a belief that there is little consistency in the fuels we buy. I once persuaded a fuel station to let me read his health and safety tome. I was amazed at the range of different chemicals that were in the fuel. I understand that some years ago the Government gave the producers more or less a free hand in what they do As all "Normal" folk drive/ride with a computer controlled Injection system that can cope with a wide range of products ,perhaps ,thats what we are getting..I know that once in the IOM my bike ran so much better. Equally many racers found their carefully set up mixtures were completely messed up. Perhaps we are chasing our tails expecting our "Iron age " mounts to cope with it when they are a little out of tune.