what does this mean .sounded as if a Muffler fell off
exhaust goes out the prop under water so it should be not loud.
maybe the motor is too high and the sound comes out above the water
if everything is in spec but still running too rich, then you may need to try another ECU
did you have the injectors tested/cleaned and make sure they are the correct ones
the stator has the charge coils, pulsar coils and lighting coils.
your service manual should give you the minimum peak voltage readings for each going to the CDI.
I am thinking this is a CDI controlled motor
