Choke?

There's you problem, there's no fuel in the carb when you try to start it. Now you just need to figure out why. Most likely (if you drive it regularly) there's a leak in the carb letting the fuel run out. You might also need to clean the fuel line between the pump and tank, you can do a rough check of flow by turning the engine over with the fuel pump outlet going into a jar. It's shouldn't take too long.

My old webber used to dry out in between uses and take ages to start but I put that down to the months of just sitting there in between runs. Not too much you can do about that.

the carb is full and and the car wont start if i crank it
but when i put a small amount of fuel in first barrel starts straight away?

looking for a weber with a12 manifold willing to pay good price

Try feathering the throttle (gently pulsing the pedal). If that fixes it you probably need to look at your choke. (I've had several cars without chokes that I needed to feather to get going.) What it's doing is using the acceleration pump to enrich the mixture.

If that doesn't work either then maybe the acceleration pump isn't working. You can check that by opening the throttle while you're looking in the top, you should see a squirt of fuel in the primary barrel.

If you have no choke, this would be normal. A good tune will help also. Lamb Daiquiri is spot on.

Also if your running high octane fuel it will be harder to start.

Lol get bike carbs, no accel pumps so need to prime carbs lol.
Combine this with 98 octane and advanced timing. ...... your issues are similar