To make this even weirder - sometimes it collapses right away from pushing the throttle - and sometimes it operates for 5-10 min and then collapses. That kind of kills the great idea of the pipe being too narrow. And yes the fuel line was replaced with a new one and the new one is the same diameter as the oryginal one.
The idea of something pinching the line has not occured to me - maybe I can reposition the fuel line under the deck - this will be my next try.
The bad thing is - I can not replicate this thing with bunny ears - it has to be in the water.....
Did not go thru all the replies so someone might have already hit on it. More than likely you have a finger filter in the gas pick up tube. Very fine cone shaped screen. Remove the tube and remove the anti-siphon valve. Then come up from the bottom of the tube with something that fits in the tube and push the screen out. Throw that away and reassemble. FRED