Fuel system problem. Please Help!

[humpinit]

Thanks for checking into my first post. I just dont know where to turn too at this point.
I will start with what I thought the problem was and procedures I took to try and correct problem.

Its a 1991 Johnson 150.
The VRO Pump has been replaced before I purchased boat with a non vro pump. Boat ran great this way for a long time.
All of a sudden it wants to run out of fuel after idleing for a about a minute.
It actually started this on my way back in one day from a trip. I had to pump the ball the whole way.
I tried different balls as I always carry a spare, but to no avail.
I was sure that the fuel pump had gone bad.
I rebuilt it and it did not help at all.
I checked all of the lines from the tank to carbs. Didn't help.
Changed the pulse indicator check valve. Didnt help.
I even reversed the check valve in case I had it backwards. Didnt help.
Bought new fuel line and pumper ball and put on a good VRO pump. (known to work). And none of this helpled.

Please any ideas that I can run through would be greatly appreciated.

[boats.net]

Well first you need to determine where the problem is, boat or motor. To check this run the boat on a portable fuel tank by-passing all boat components. (from tank straight to motor). If the problem persists then there is a problem in the motor. What is your model number?