Have a 2008 130 Whaler with 40hp Merc, came with the boat. Will run at speed no problem, but as soon as you try and troll it will start shaking with a knocking sound and die. Local mechanic (Merc dealer) cannot diagnose, good compression and as I said, runs great while at speed. Sometimes will troll for a few minutes but will always go to this condition soon. After starting, it will run for about 45 seconds in neutral, enough time to put into gear to go at speed. but will die within a minute if you let it idle.
Any ideas?
Any ideas?
