Outboard dies after a minute or two of running?

[dustindaugherty26]

Have a Johnson 50hp from early 80s. I took it out the other day. Pumped primer ball. Engine fired right up. Ran for about 2 or 3 minutes at full throttle traveling across lake then seemed to drop to half power for about thirty seconds, then quarter power for thirty seconds then died. Refired a few times and would die as soon as I attempted to put it in gear. Then had trouble starting at all as if it were flooded. If I let set for a few minutes would fire up for a few seconds and die again.

Some things I noticed: At home I could fire it up and let it sit at idle. Would run for about a minute and then slowly lose power and die over the course of 30 seconds or so.

Primer bulb never got “hard”. Always felt somewhat soft. I could hear fuel spraying into carbs while pumping ball and not running. Tried pumping while running, no better.

No leaks in engine that I could detect. Possible small leak at hose to tank hookup point when pumping ball.

If I pump ball with hose disconnected from engine but not tank it gets solid as a rock.

Could this small leak be enough to cut engine out every time so quickly?

 

[tpenfield]

Check . . .

Fuel pick-up in the fuel tank
Fuel lines - both from the fuel tank and the small section of line around the engine.
Fuel filters - both external and there may be a fuel filer/screen in the carburetor(s)

The issue sounds like fuel starvation and that is a terrible way to die.

When the engine starts to loose power, does pumping the fuel bulb help?

 

[racerone]

The bulb MUST go hard.-----So there is a leak.-----Check carburetor floats.----Check fuel pump diaphragm for a hole or tear.-----Inspection should be done before rushing out to buy parts.