Thanks for the advice from some of you I may have sorted the problem. I stripped the carbs and found that one of the needle valves was sticking slightly, I tried to free it but it still sticks, so I ordered a new one at £14.95 yes £14.95 for that little thing. Hoepfully that will sort it.
Cheers guys
Rescued attachment P1000832.JPG

Doesn't that bit sit in/on the float? If not, what was it sticking against? (Just curious really)

yes it sit in the float, the little piece at the end where the arrow is, is spring loaded and it should shut the fuel off in that chamber when full, but it is sticking so its over filling the float chamber. I THINK

Just wondered what fuel pump you are using ? We ran a facet at first but this would over power float nedles & just poured fuel down the carbs - ok flat out, not too good on tick over!! now running two bike pumps to get fuel up to carbs & keep them fed.

it's just the standard blade pump.

I only ask, as with most carbs I've taken apart, the black end is the seal. Can never remember the name of the stuff it's made of though, but it should sit into a hole in the carb and shut off the fuel. What does seem to happen with these things is that the bit you've got n the pic gets gunked up and sticks in the tube it sits in.