I have a new to me 2000 50hp 4 stroke bigfoot. The carbs were dirty so I cleaned them in a sonicator and replaced the nozzles. All the jets were clear but carbs 1,2,&3 had the wrong nozzles and the nozzle in #4 was in two pieces. Motor has good compression, starts fine and has a smooth idle but it lacks power (stays around 3000 rpm). I have checked the stator, fuel pump, coils, thermostat, and tried new plugs but no difference. Squeezing the ball while running has no effect. I don't know for sure but I suspect the previous owner had this issue as well. I am at a loss as to what to try next, any ideas????