Thanks for that. Had it checked by Mariner dealer and no fault was found. During normal operation it is fine. I had a 2000 model but this had carbs so when decelerating hard the engine did not cut as quicky due to the damping. With the EFI it cuts real quick, obviously it is not something you do often anyway. Only noticed it when I had to decelerate quick.
The engine itself I am well pleased with. Starts first time every time, stable idle and very smooth, quiet and economical.