93 evinrude tracker 115 WOT problem

[arielmechanic]

I'm new to boating and I'm having an issue with the engine on my boat. I have a 93 nitro with an evinrude/tracker 115 v4. My father gave me the boat after buying himself a new one. He got the boat used. At some point the VRO was disabled and the fuel pump replaced with a non oem part. It is a pulse operated diaphragm style pump. The problem I am having is I can run the engine at WOT after launching for a couple miles and it runs fine. After fishing a while, I'll restart and try to run at WOT again. Usually it will plane out and run maybe 200 yards then lose power. If the throttle is left wide open, the engine will die. If I have someone in the boat with me, they can pump the primer bulb up and it will pick up speed and run another 200 yards. In my mind, it needs a fuel pump, but before I spend a hundred bucks on a pump, I'd like some input from others that may have had similar experiences. Thanks in advance

 

[Auxlarry]

Re: 93 evinrude tracker 115 WOT problem

It could be a few things besides a fuel pump. Have you replaced all the fuel lines from the tank to the engine? Have you checked to see if you have an anti siphon valve in the tank that may be slightly restricted or malfunctioning?
Old fuel lines or bad clamps, especially on the suction side of the fuel pump, may be allowing air to get sucked in with the fuel and causing your problem.
Check these areas first and do a compression check on the engine and let us know.

 

[arielmechanic]

Re: 93 evinrude tracker 115 WOT problem

The anti-siphon valve was sticking. I replaced it. The pickup tube in the tank was clean and in good shape, no holes or cracks. I checked the tank vent. It was free of debris. I replaced the bulb and fuel hose clamps. The hose isn't very old, but it wouldn't hurt for me to replace it. I have not checked compression, but i will and report back. Thanks for the input.

 

[emdsapmgr]

Re: 93 evinrude tracker 115 WOT problem

On occasion, the ball valves in the bulb in the hose will go bad. Did you try a different hose? If the engine will pickup and run full throttle while someone constantly primes the fuel hose bulb, it's possible that you have a weak fuel pump.