Having stripped it down and decoked it , replaced piston rings. I took the carburetor to a technician for a sonic wash. He immediately spotted that the choke lever was bent and was obstructed from fully opening this would cause flooding and simalar symtoms to my description of my problem. He made adjustments to lever and returned it for me to refit and try out, will let you know what happens.
David Evans UK, March 2011
