Bowls not filling up with fuel. Any suggestions?

Need some help here. Hav'nt worked any carbs for 10 years or so. Been messin with FI all this time. Anyway, have a set of 77 CB 550 carbs. Just cleaned everything up. Floats looked OK needles seamed to have good "bounce" should not have been that far off. But 3 of the four bowls where empty when I tried to start it tonight! Where should I start??

Fuel tank and lines?

tank has fuel, running clear lines can see fuel in the in line filter and supply lines

When you say float bowls look okay, do you mean they are at the right height? Also make sure the plunger is not jammed in its hole and the spring valve is still working.

It is easy to 'pinch' the float bowl gaskets when assembling causing them to bulge inside the bowl touching and jamming the float.

But first, just try tapping the side of the bowl with a screwdriver handle or similar. Sometimes thats all it takes.