1987 force 50 progressive power fade to dead

[inquizito]

I am pushing a 15 ft. Sportcraft with 2-cylinder 50 HP motor (507F7C). It initially worked well. Then, a few weeks later, I discerned a slight power loss at full throttle. That became a clear power loss noticeable at 3/4 throttle, then 1/2 throttle. And at 1/4 throttle. Then with minimal throttle, the power faded and the boat left me stranded and would not restart. I have guessed at coils, rectifier, stator, or voltage regulator as possible sources of power failure due to inadequate charging, as I have found the battery below 12.8 volts after getting stranded. Should I be recharging this (Nautilus 1000) battery each time I take it out, or should it be recharging itself if all electrical components are optimally functional? Do I start with a new battery or with electrical items ?

 

[inquizito]

Re: 1987 force 50 progressive power fade to dead

I noticed looking under the stator that there are areas where the copper binding appears to be missing - is this is the design (perhaps for balance) or has part of my charging system flung?

 

[inquizito]

Re: 1987 force 50 progressive power fade to dead

the small, square sections where copper is missing are in multiples of 4-5, and then there are several intact copper bindings before another apparently missing 4-5 - does anyone know why is?

 

[inquizito]

Re: 1987 force 50 progressive power fade to dead

Many people know rehearsed answers, but few are practiced and capable diagnosticians, and I am certainly NOT - I have only taken this thing out 3 times, last time stranding my family visiting for Easter from out-of-town. What are the variable with which I should be concerned - and does this seem more electrical or fuel in nature??

 

[catfish1]

Re: 1987 force 50 progressive power fade to dead

could be either spark or fuel, first do a spark test. take the plugs out and ground them against the block, check for spark on both plugs.<br />if you have spark it should fire with fuel, put a little premix fuel in the carb throat and see if it cranks up! if so, you have a problem with the fuel. check everything out from the gas tank to the carb, if you find nothing it could be an obstruction in the carb or possibly the fuel pump. hope that helps

 

[inquizito]

Re: 1987 force 50 progressive power fade to dead

thanks! .checking that today...

 

[inquizito]

Re: 1987 force 50 progressive power fade to dead

Well, for anyone who might run into the problem I did, here is the solution I found: There are 3 valves in the fuel pump. 1 is held in place by two very small screws - 1 screw slipped loose, binding in the valve entrance port, eventually not only causing a restricted fuel supply (poor throttle response at high speed when screw was becoming trapped in valve port at higher vacuum),<br />but eventually a bigger problem: The screw tore through the fuel pump diaphragm, leading to a no-run condition, unless you consider running with choking the engine incessantly running, with re-starts every few minutes. A replacement of the screws to the proper location seating that valve,<br />and a new fuel pump diaphragm and its gasket, and it has never run better. And I have learned.