I own an 1988 255 Sprint with an 1988 80hp mercury motor.I can be pegged out going down the river then all of the sudden the boat will bogg down to about 5-10mph full throttle.I pull the plugs, clean them off and she runs like a top.Usually,it will run fine the rest of the day.I've also had this problem straight off the dock.Any help would be greatly appreciated.I have also noticed that when I put in and the motor is trimmed way up it won't start then I trim it down and it will fire up.(Possibly a whole different problem)
