1987 evinrude runs then dies

[Ttrov22]

Please help. 1987 evinrude outboard will start every time, run for twenty second then dies. Model number is e40ecud. Boat mechanic cleaned the carbs and replaced spark plugs. After I got it home I started it and it ran for a 20 seconds then died. Figured it was a fuel issue so I've replaced the primer bulb, gas tank fitting, fuel filter and rebuilt the vro fuel pump.(vro is disconnected running 50:1 mix) after all that boat still dies. Sent back to mechanic and he claims that its the fuel pump. Picked boat back up before he did any work to check pump. Disconnected line from pump to carb and pump put out 2 fl oz on twenty seconds before it died. Did the same thing three times with the same result. Boat will die regardless of i pump the primer bulb or not. Is the pump the issue or should I be looking elsewhere?

 

[racerone]

Pumping the primer bulb should put fuel into the carburetors.----------So look elsewhere for the problem.-------Hook up a timing light and see what happens to spark when motor dies after 20 seconds.----Does it die like you turned the key off ?----Also look inside your fuel tank for leaks / bad pick-up tube ?

 

[James R]

Been getting fuel supply problems on several boats lately. Try putting the end of the bulb hose in a gallon jug of fuel mix and see if the motor will run. If it does then the problem is tank side.

 

[Ttrov22]

Thanks I'll try that but I was leaning more towards a stuck float. The motor will run for 20 to 30 seconds then sputter and then eventually die. Could a stuck float cause the motor to eventually flood after 30 seconds and then cause it to quit? When it starts to sputter choke only makes it worse making me think the engine is flooding. Thoughts?

 

[racerone]

2 hp or 250 hp

 

[Ttrov22]

40hp 1987 evinrude

 

[racerone]

The motor will run on one carburetor.---I doubt that both float valves are sticky.---Put fuel tank above the motor and test run at idle.---And hook up the timing light as suggested and look for spark issues too !!