Stalling at half tank only when trying to get on plane

[Helipilot]

Hello everyone,
I came here to post this because no amount of google searching could find anything like this. So here is my problem...
My boat is a an 1988 sport craft avanti 250. The motor is 5.7l cobra. I am a boating newbie so please forgive me I leave out any import info. Anyway the boat runs GREAT as long as it has more than half tank of gas. As soon as I reach half tank and try to get up on plane when the bow is high in the air the motor will stall or least hesitate until the bow drops down again then. It will run fine for the bottom half of the tank if I keep the speed slow enough that the bow won't rise. Its almost as if the fuel pick up in the tank is at the front so when the fuel sloshes to the back it starves the motor.
I bought the boat with this problem so I can't say how long it's done this for and the previous owner has passed away.
The last thing to mention is that The fuel tank seems inaccessible without removing the kitchen.
Any help would be appreciated, until then I will just keep it filled past half tank.

 

[Boobie]

Can you get at the pick up in the tank ??

 

[Helipilot]

I'm not sure. Again I'm a boat newbie but I can follow the fuel lines from the motor or the filler and then I loose them when they go under the floor. I can't see any inspection port so it looks like the only way to get to the tank is to pull up the floor which is under the kitchen.

 

[Boobie]

Get a second opineon from somebody else in the marine business who can look at the boat.