MikeYZF13

Forgot to say its a 1998 s reg

hi all ive got a yzf thundercat it has been off the road for quite a few years i have had the carbs off and cleaned them up, the bike now starts and runs ok, but with the fuel pump plugged in after a minute or so it starts to flood the bike up to the point where it dies and wont start again. but if i unplug the fuel pump and clamp fuel hose, spin it over full throttle it then clears the flood and fires up, with the fuel pump disconnected it will sit there running perfect and will rev up perfect and dosent flood up at all basicly has anyone had this before as id like to no if people have just unplug and bypassed the fuel hoses from the pump before the bike isnt ready for the road yet so i havent tried it on a run, this is just at idle and reving it just after some ideas as to what to do next, this may be a common thing with them but i dont no lol so hopefully someone on her does cheers mike