Despite it being a great day for being out on the bike, the blackbird had to watch be perform surgery on its garage mate lol. Changed the plugs as a default, checked all the pipes etc as you suggested they seem to be ok.......
fuel pump - stops and starts when you block and unblock the outlet although it "knocks" when it runs ( same as when engine is running) can feel it with a finger. as for the pressure, dont have a gauge so cant check it.
i will pm you my email as i would love the kwack manual i can at least then check the relay for spec.
failing my efforts it is provisionally book at gp autos in cricklade