Pro 50 RPM fading problem

[NWTBoating]

HI All! I have a 1991 Pro50 on a 16ft Mirrorcraft Troller XL. I have a 15x10inch prop on it (speed prop). I can get 5000-5200rpm max out of it. The motor has run perfect for many hours now but the last time I took it out I had this problem. I has a fair bit of weight in the boat and only could get about 4700 rpm, which is understandable I suppose, but after a few minutes at full throttle, the rpm would begin to drop and the engine would bog. Then if I pulled the throttle back for a second and retried it, the motor would work fine for a few more minutes, then the same problem. I checked the fuel filter. Not the problem. I checked the lines, no leaks or air being sucked in. The plugs seems alittle fouled, but not bad. <br /><br />Here is my question: Would the extra weight and subsequent lower RPM have caused the motor to flood itself alittle bit, causing the bogging down? Any thoughts as to what I might be able to check next?<br /><br />I appreciate any help on this one!!

 

[NWTBoating]

Re: Pro 50 RPM fading problem

One more thing. I do not think it is the fuel pump diaphram becasue when it bogs, I tried squezzing the bulb to see if that would give it more fuel. It did not make a difference. Also, the air valve was open one the fuel tank.