I have a 1988 aluminum bass tracker guide-V 16ft that still had the original 25HP Merc 2 stroke on it. That engine was pretty tired (couldn't get it to run good low speed or at idle it needed an overhaul). Anyway, the boat loaded with 3 people and all of our fishing stuff would go 16-17mph and low 20's with less weight. This year I purchased a new 2011 Merc 4-stroke, EFI, 30HP, power trim. Put a couple of break-in hours on it and tried to see how fast if would do. With the same amount of weight as with the old motor, it only did like 9mph full throttle. Tried changing the trim to the second hole from the top (which is how the old engine was set) and only picked up another 2mph at best. My question is....What Gives?!?! This is a brand new engine rated at 5 more hp with an identical prop (3 blade, 11pitch). The dealer gave me the option of a 9 pitch prop. Would that make the difference with this 4 stroke? Any ideas on what to change for more speed would be greatly appreciated. Thanks.
