air in fuel filter

[Precast]

I have a 2001 2 stroke Yamaha that has a see through filter attached to the port side of the engine. While the engine is running the gas level drops down about a third of the way resulting in a loss of rpm at high speeds. When you pump the ball it fills completely but then slowly decreases. I have replaced the filter and seals in this filter, replaced the in line water seperator filter and replaced the primer bulb. I have also inspected the hose from the tank to the engine and can't detect any leaks.

Any ideas?

[Tucker]

Sounds like the fuel pump is bad.