Hi everybody,
I'm got a 1971 Johnson, 25hp outboard that I have been going through and fixing up. I have rebuilt the carb, being very careful to clean out all passages, made sure the float was set correctly, and made sure the low-speed needle and packing was in good shape. I've completely replaced the points, condensors, coils, plug wires, and plugs. I've put in a new thermostat. The motor starts just fine, and idles well. It will run at top speed very well, with no stumbling. My problem arises when I try to accellerate rapidly from low speed to high speed, as well as when I drop from high speed to low speed. The motor will start stumbling and in many cases "bog-down" and die. It will start back up just fine. The problem doesn't seem to go away over time (once the motor is warmed up and the thermostat opens, it still does this). If I accellerate/decellerate very gently, it seems to do ok. I have tried pumping the primer bulb when this is happening, and it seems to kill the engine quicker. The only thing I haven't looked at on this motor is the fuel pump. Do these symptoms sound like fuel pump symptoms, or does this point back to the carb? I was very meticulous when tearing down the carb...
Thanks a bunch,
Ken
I'm got a 1971 Johnson, 25hp outboard that I have been going through and fixing up. I have rebuilt the carb, being very careful to clean out all passages, made sure the float was set correctly, and made sure the low-speed needle and packing was in good shape. I've completely replaced the points, condensors, coils, plug wires, and plugs. I've put in a new thermostat. The motor starts just fine, and idles well. It will run at top speed very well, with no stumbling. My problem arises when I try to accellerate rapidly from low speed to high speed, as well as when I drop from high speed to low speed. The motor will start stumbling and in many cases "bog-down" and die. It will start back up just fine. The problem doesn't seem to go away over time (once the motor is warmed up and the thermostat opens, it still does this). If I accellerate/decellerate very gently, it seems to do ok. I have tried pumping the primer bulb when this is happening, and it seems to kill the engine quicker. The only thing I haven't looked at on this motor is the fuel pump. Do these symptoms sound like fuel pump symptoms, or does this point back to the carb? I was very meticulous when tearing down the carb...
Thanks a bunch,
Ken