2003 Mercury 3cyl 90 HP boggs down at higher rpm

[tuggator]

....and runs itself out of gas / as if startving for fuel?


Any Ideas Gents?
The engine was stalling out at higher RPM as if it were starved of fuel or air?

I just replaced the on deck fuel line and used new clamps for good connections to increase fuel flow.

My troubleshooting test runs found that:
Engine starts right up does well until about half speed, and she starts starving for fuel. Before I replaced fuel line and bulb, the old bulb was collapsing as engine would loose rpm and sputter. As I would back off on the throttle the engine would catch up on fuel and not have any problems running. I opened the (internal) Fuel tank fill while underway (the vent for the fuel tank is in the fill cap aswell) at speed and that did not improve the sluggish cyclical speeding up and slowing down of engine while at WOT. Another test I performed was having someone else run the boat while I pumped the primer bulb and I think that helped out. I have never had this problem before.


To Remedy this situation should I....?

1 Relace the inline fuel filter
2 I may have to replace from the tank to through deck nipple.
3 Replace the fuel tank pick up
4 Rebuild / Replace Fuel Pump

I am open to any and all suggestions. Thanks in advance.

 

[Silvertip]

If the primer bulb goes flat the fuel pump is not the problem -- that's what is sucking it flat.. There is restriction between the bulb and the pickup in the tank. Disconnect the fuel line at the tank, remove the anti-siphon valve if there is one, and blow compressed air into the tank after making sure the vent line is clear. Check for debris in the anti-siphon valve and push on the check ball to make sure it moves freely. Replace it if necessary. If the primer bulb firmed up quickly there is likely no need to replace it although the fuel line could have collapsed between the tank and the bulb. If there is a filter between the tank and the primer bulb, check or replace it. Any filters after the primer bulb would not cause the bulb to collapse.

 

[tuggator]

Silvertip

Thanks for the heads up. I appreciate your input. Im off to my boat to work on it. Thanks Gator!

If the primer bulb goes flat the fuel pump is not the problem -- that's what is sucking it flat.. There is restriction between the bulb and the pickup in the tank. Disconnect the fuel line at the tank, remove the anti-siphon valve if there is one, and blow compressed air into the tank after making sure the vent line is clear. Check for debris in the anti-siphon valve and push on the check ball to make sure it moves freely. Replace it if necessary. If the primer bulb firmed up quickly there is likely no need to replace it although the fuel line could have collapsed between the tank and the bulb. If there is a filter between the tank and the primer bulb, check or replace it. Any filters after the primer bulb would not cause the bulb to collapse.