1995 25 HP Johnson loosing prime

[JIM4475]

I have a 25 HP elect start, that will run all day at idle, trolling, but when I take off and run at WOT or just plain off if I don't reach back and pump the bubble while it is running it dies after a minute or two. I have a new single fuel line with new connectors, what else could be the problem? Possibly the fuel pump?
Any info is appreciated.
Thanks Jim

[marinemech1]

if you have a plastic tank- check the fuel pick up for cracks

[Joshua B]

Your feul pump may be the issue, if not, I would try running with the cowling (hood) off. Some motors release exhaust fumes into the powerhead area and choke the airflow.

[tashasdaddy]

float needle sticking in the carb. the pressure of the pumping may be forcing it open. air leak in fuel line. vent not open on tank.

exhaust problem, would not be corrected by pumping the bulb, that would need fresh air.

[JIM4475]

Thanks guys I plan on checking all the gas lines this weekend. The vent was the first thing I checked. Carb was rebuilt about a year ago with regular use sence, I think it is most likely a air leak in one of the lines or connections.