IAM NEW TO THIS WHOLE BOATING THING. I HAVE A 19'BAYLINER WITH A 125 HP MOTOR.SO FAR EVERYTHING HAS WORKED PRETTY WELL. THE MOTOR STARTS AND IDLES FINE, IT SEEMS TO RUN GREAT AT FULL THROTTLE.I HAVE TO TRAVEL ABOUT 45MINUTES IN A CANAL AT ABOUT 5MPH TO GET TO THE RIVER. AT THAT SPEED THE ENGINE SEEMS TO HAVE AN OCCASIONAL SHUTTER. IS THIS JUST ONE OF THOSE SPEEDS THAT THE ENGINES DOES NOT PERFORM PERFECTLY? I GUESS EACH ENGINE HAS ITS OWN LITTLE WEAK SPOTS.