When going across the water in my 75 horse Mariner I started losing power. I noticed that the primer bulb was totally flat like plastic bottle that someone sucked the air out of. Any ideas about what is going on?
Agree, your fuel tank isn't venting. Easy thing to overlook, and one of those "DOH" moments when you discover it. I stalled out one time, looked at the plastic Attwood fuel tank, and the sides were all sucked in like a cardboard box that someone had sat on! Dummy.
If you don't have an anti-siphoning valve, then check the gas cap itself. The cap is supposed to allow air in and if it is plugged, it will such the primer bulb flat like you stated....