I have a 1989 Johnson V4 140 which runs fantastically well - but only when it wants to! It will suddenly lose all rpms and not go above 3000 rpm. I have changed all the fuel lines, added a fuel filter, added a new fuel tank, changed all plugs and leads and cleaned out the carbs! Still it will not run well under load. It almost seems to cough and splutter and then fade away. Does anyone know what I can do as it is driving me crazy!
