I have a suzuki bandit 400. i place my gas tank on the motercycle and after it burn the gas it has in the carbs it turns off. then i force gas from an external bottle in the gas tube to the carbs and it starts working againg till it burn that gas two then turns off.

Have you pulled the line from the petcock and checked for fuel when you turn it to on or reserve?
If you have fuel flow then maybe the floats are stuck blocking the fuel from filling the bowls. Tap on the float bowls with the handle of a screwdriver. Also if your carbs have a drain screw on the bowls open them and see if fuel starts to flow.
I don't recall if your bike has one, but I have seen few carbed bikes with electric fuel pumps as well. If yours has one then that is for sure something to check into.

You may find the petrol filter is blocked. That is usually at the top of the petrol tap in the tank. Unscrewing the petrol tap will reveal it.
I always recomend the manufacturers parts as they have more expertise than us!
Fit original carburettors, they were designed for the engine after all.

Carb would be the place to start assuming it was running fine before it was stored. Gas can "varnish" in carbs while in storage for long periods of time if a fuel stabilizer wasn't added before storing. Might try some fuel system cleaner before going to the trouble of removing the carb.

i think the fuel filter inside the tank is dirty, or the fuel on the float bowl of the carb is low that when you give gas the fuel in the bowl runs out.

remove carb bowl and clean it and the jets with carb and choke cleaner, put fresh gas in tank to ensure its all good

Once you remove the gas tank, it will be very obvious. Cable easily comes out of the thumb mechanism easily when you take it apart.

its still sucking in air try using a thicker gasket and taking out the "o" ring this may seal the air leak its that or a replacment carb

possibly **** in your tank which has blocked your jets in the carb, clean out tank and fit an in-line fuel filter and clean carbs, imports often did this due to rust inside tank, if its bad take off tank and put in an old bike chain with some oil and shake the **** out of it, flush it out and drop an old speaker magnet inside tank to colect any rust in the future then fill it back up with fuel

hi worth while getting the carbs balanced
cheers jay

Maybe some water in an electrical plug. Remove the tank and dry it all out with compressed air or WD40. Work around the coils and other wiring. Also where the wires come out of the engine case.