Can a non-stock fuel filter cause starvation?

[sailincpa]

I bought a 25-year old Evinrude 2HP, with an integral fuel tank on the top of the motor. It's a gravity feed fuel delivery (no fuel pump), so the only force delivering fuel to the cylinder is gravity and the vacuum of the cylinder rising pulling fuel Into the crankcase thru the carb. Runs great at idle and up to about 2/3 throttle, but when set to WOT, the motor stalls after running for a couple minutes. I've rebuilt the carb (twice), decarbed the motor, replaced plug and checked gap (.030), checked spark strength (jumps nearly 1/2"). Copmpression is good (110). The prior owner installed a non-standard in-line fuel filter in the fuel line between the tank and carb. The filter bowl is a clear see-thru, and I've noticed that when running it's maybe 1/2 full with fuel, no more, even though the syphon effect would say it should be full. Seemed to run better (but still not at WOT) when I replaced the filter with a straight fuel hose while de-carbing. Could the slight additional resistance to the fuel flow of this non-standard filter be the problem? (I suppose I could just replace the filter with straight hose again, but the motor's down at the boat a half hour away, and I'm thinking of it now, I knew some of you guys would have experience with this.)

 

[JB]

Re: Can a non-stock fuel filter cause starvation?

I think you have a failing water pump, CPA.<br /><br />Easy replacement when you use the Manual.<br /><br />There should be a filter screen inside the tank as part of the outlet attachment. You need to check that. The aftermarket addition could be a replacement for a missing in-tank filter. I think it is unlikely that the aftermarket filter is causing your trouble.<br /><br />This is an outboard trouble topic, so I will move it to JohnnyRude Troubles.

 

[Silvertip]

Re: Can a non-stock fuel filter cause starvation?

Is the tank vent open??

 

[R.Johnson]

Re: Can a non-stock fuel filter cause starvation?

Personally! I don't like in line fuel filters. If you have one in the fuel tank, another in the fuel pump. How many do you need? When does that filter become a restriction. They talk about fuel line size, then choke it down with filters, and quick disconnect's. These engines need clean flow, and the less restrictions the better. That means less connectors of any kind.

 

[umblecumbuz]

Re: Can a non-stock fuel filter cause starvation?

I agree with RJ.<br /><br />A large percentage of breakdowns are fuel-related.<br /><br />Just take care to keep the tank clean inside, and filter the fuel that goes into it in the first place.

 

[sailincpa]

Re: Can a non-stock fuel filter cause starvation?

Looks like JB is right, there is no in-tank filter. But still don't understand- tank vent is open, water pump OK (although I don't see why that would cause high speed stalling - it's not overheating and will happily run for 45 min or more at 1/2 throttle), and there is no fuel pump, therefore no filter in the motor.

 

[OBJ]

Re: Can a non-stock fuel filter cause starvation?

The intank filter is a small screen which is part of the shut off valve assembly that is screwed into the under side of the tank. Hard to see even with the tank MT. If your sure it's not there, you might want to drain the tank and and remove the shut off valve for any debris that may be clogging the inlet side of the shut off valve.