Fuel problem at full throttle

My 1996 50hp Johnson is losing power at full throttle. It cranks great and idles great. Sometimes it takes off and runs full throttle, but then dies down to about half or one-third throttle at times. When it is doing this, you can choke it and it takes off for a burst, but then dies down again. While acting up, sometimes if you pull back on the throttle it will pickup speed, but then die back again. <br /><br />I have checked the fuel filter. <br /><br />It has a new external tank, and new gas.<br /><br />Also, tried fuel tuneup through the carb/choke port.<br /><br />Any chance it is the fuel hookup to the tank?<br /><br />Pump up ball never really gets hard either?<br /><br />Thanks, Clark

Re: Fuel problem at full throttle

Welcome to iboats Clark!<br /><br />Start with the fuel delivery hoses and primer bulb. When this condition occurs, will the engine pick back up if you squeeze the primer bulb? Empty the hose and shake the bulb. If one of the check valves have fallen apart, you will hear the ball bouncing around. Squeeze the bulb and you can feel it.<br /><br />Check all fuel lines at the engine are tight and none have gotten hard. Replace any that have. Check for leaks.<br /><br />Make sure the tank is vented!<br /><br />Hitting the choke and the engine picks back up, on most occasions, signals a restriction in the carb....usually a gummed up high speed jet. But we need to check these other points first. <br /><br />Hosing out the carb throats with cleaner don't help. You gotta get the stuff in the carb bowl. A good carb cleaning and overhaul is usually the best way to go to get the carbs back to norm.

Re: Fuel problem at full throttle

I checked the primer bulb. It seems to be fine . . . no problem with the check valves. <br /><br />However, upon priming I noticed a small amount of fuel seeping out (with a little air) around the motor side of the primer bulb (where the fuel line attaches). <br /><br />Also, when I disconnected from the fuel tank, a little fuel and bubbles came out of the female connector on the fuel line. Not sure if that is normal. <br /><br />Upon inspection of the fuel line, it is breaking down on the outside, with alot of black residue and flaking in a few spots. I'm going to go ahead and replace the entire line, primer bulb and female connectors. <br /><br />Also, when I disconnected the line from the bulb, there was a tremendous amount of pressure between the primer bulb and the motor . . . sprayed everywhere, is that normal? I had just primed it checking the bulb.