thanks to adam the bike doctor.re-vmax?

took the advice and did not shoot the vmax.the problem in the end was the carbs.i carried out a total strip down and found on both the left hand carbs the pilot air jets were fould up.the springs were rusted to the tiny washers on their bases.cleaned the jet and replaced the springs.on the same two carbs one had a pilot jet hole completely blocked and one half blocked. serious cleaning was carried out.after refitting and two pushes on the lecky start she fired up on all four cylinders.after standing running for ten minutes i synchronised the carbs, every turn of the adjusters making a big improvement,after a few blips of the throttle and setting the idle the engine runs spot on.your helpful advice was greatly appreciated.if you were not 120 miles away i'd buy you several lemonades.cheers mate.