Vfuschetti
New member
I have a 1978 115HP Evinrude that runs GREAT until I have a large load on the prop (4 adults on the boat 2 teenagers on a tube) or on plane at full throttle and then she will intermittently stumbles but only ever so slightly. Under extreme load however, she will bog and not respond to throttle inputs while the engine loses rpm until the throttle is pulled back and the load is removed. At 4500 RPM she will run all day long without a hiccup.
I have removed the inboard aluminum fuel tank, flushed it, confirmed the pick-up tube and vent are functioning properly. I have replaced all the fuel lines, bulb & connection between the tank and the engine. I have replaced the fuel pump and fuel lines from the engine connection to the pump and to the carbs. I have removed and cleaned the carbs which looked 100% perfect and confirmed the float setting. The spark is perfect on each cylinder, and I have 120 lbs of compression across all four cylinders. I also replaced the rectifier (battery not charging). I even put an inline fuel pressure gauge between the bulb and the engine connection and saw about 4 lbs of pressure. (is this normal?). Bottom line, I don't know where to go next. Any help/suggestions/ comments or questions would be helpful. I'm considering rebuilding the carbs.
I have removed the inboard aluminum fuel tank, flushed it, confirmed the pick-up tube and vent are functioning properly. I have replaced all the fuel lines, bulb & connection between the tank and the engine. I have replaced the fuel pump and fuel lines from the engine connection to the pump and to the carbs. I have removed and cleaned the carbs which looked 100% perfect and confirmed the float setting. The spark is perfect on each cylinder, and I have 120 lbs of compression across all four cylinders. I also replaced the rectifier (battery not charging). I even put an inline fuel pressure gauge between the bulb and the engine connection and saw about 4 lbs of pressure. (is this normal?). Bottom line, I don't know where to go next. Any help/suggestions/ comments or questions would be helpful. I'm considering rebuilding the carbs.