79 15 HP Johnson won't draw fuel from tank

Ok guys ; I have a 79 15 hp Johnson electric start (15E79) ran fine the first time out this year. The next time engine would run for 5 minutes then die. I check the fuel line and there was no pressure in the primer bulb,pumped it up, started and ran for 5 minutes. No pressure in the primer.
I rebuilt the fuel pump, but hat did nothing for the problem. I then changed fuel tanks, again no help,got a new fuel hose, again no help.
I am at a loss. The engine runs till it draws all the fuel from the line but wont draw fuel from the tank.
Any help will be greatly appreciated.

I got a new hose that did not help. I will try bypassing the connector on the motor to see if that corrects the problem.
Thanks for the info. All I can do is try something different.

Thanks for the help. I removed the fuel lines under the hood, they weren't leaking, but when I put them under pressure found a pinhole in the feed line. Replaced both lines and clamps and tested with muffs, as for now it is working. Tomorrow on the water for the real test. Thanks again