Fuel Starvation?

[jlgetgood]

2014 Bass Tracker 170, 40hp 4 stroke merc. Runs and operates normal. Reducing throttle motor begins running rough and die. Restarts fine, idles well, stumbles when applying power. Reduce throttle and motor dies.

 

[jlgetgood]

Another observatio; the fuel level in the fuel filter bowl is low when engine dies.

 

[QBhoy]

Hi. Are you running from a remote fuel tank or an inbuilt to the boat tank ?

 

[mike_i]

Is the vent system clear? Try running the motor with the gas cap open. Does it run if you squeeze the primer bulb?

 

[jlgetgood]

Hi. Are you running from a remote fuel tank or an inbuilt to the boat tank ?

built in tank

 

[jlgetgood]

Is the vent system clear? Try running the motor with the gas cap open. Does it run if you squeeze the primer bulb?

I will try open cap. Yesterday replaced fuel bulb as existing seemed plugged some. I removed the fuel cap to add Sea Foam and there was pressure in the tank. Is this normal?

 

[jlgetgood]

I will try open cap. Yesterday replaced fuel bulb as existing seemed plugged some. I removed the fuel cap to add Sea Foam and there was pressure in the tank. Is this normal?

After Sea Foam and new bulb runs better but still sputters when reducing throttle.

 

[QBhoy]

I will try open cap. Yesterday replaced fuel bulb as existing seemed plugged some. I removed the fuel cap to add Sea Foam and there was pressure in the tank. Is this normal?

Is the fuel priming bulb the right way around ? Easy to get that going the wrong direction occasionaly

 

[jlgetgood]

Happy to report that either fuel bulb/hose or sea foam has it running great

 

[QBhoy]

Happy to report that either fuel bulb/hose or sea foam has it running great

Excellent. Be almost sure it was the fuel bulb perhaps. Great result

 

[Texasmark]

Go 2 steps farther:
1. Disconnect the fuel line from the engine and squeeze the bulb. If using a connector, have someone depress the center pin (so that fuel will flow when commanded). You should get a good fuel response and no tan crystal/crunchy material.....nothing but clear fuel.
2. Replace the engines (and any water separator/filter cartridge if so equipped, checking the sump for residue) fuel filter and cut the old one open. If little black specks are in it replace the engine fuel lines. If the above tan material chips are in it replace the entire fuel line from the tank to the engine.