Stalling under full throttle

I have a '79 Thompson with the 260hp OMC 350. Running at full throttle the boat will suddenly die. It is hard to get restarted but once I do it will die as soon as I give ANY throttle. After a few minutes of just idling once restarted I can throttle back up. But within 30 seconds its dead again. Once I pulled the fuel line just before the filter and found it to be void of fuel. I could not blow back into the tank. I checked the tank and found no obstructions, either in the tank or the line. I'm not new to engines but am new to marine applications. Anyone have a similar problem or any ideas what to check next? Replaced lines, filter etc.

 

If the tanks seals tight it may cause a vacuum the fuel pump cannot pump fuel to the engine. Does the tank have a breather ?

 

definitely sounds like fuel starvation issue. It could be the lack of replacement air or something else.

 

Fuel problem most likely. Can't deliver enough fast enough. Fuel pump or clogged fuel filter.
Probably.

Alan