really need to mount it on a test stand and run it in first.
makes it easier to adjust. it will start up very rich, and it will need to be leaned out gradually.
after a tank of fuel start to lean it out. gradually. by the third tank,
it should be mounted and lean enought to fly. but some go more, and some go less

that vent line in the back should be open to atmosphere..short piece of line on it.
thats where the crankcase vents, used lubericant is expelled there.
those filler valves are known to leak sometimes. leak air.
i would suggest trying without using the filler valve, bypass it.

are you using an electric starter? if not. i would find one
it makes the whole operation easier.
if your fuel lines are connected correctly and no air/fuel leaks, it should
pull fuel just by propping it over 5 or 6 times with your finger over the muffler outlet.
my 100 started right up. when it was brand new.
no fuel coming thru the line makes me think you have an air leak.

just some ideas. All my Saitos when new where very easy to crank the first time