Avon 620 open adventurer Yamaha F115 4 stroke
Bought this bought about a month ago and loving it with the family. The only thing is when I 1st bought it it would do about 33 mph at WOT (5000rpm). A month on it is only doing about 25 mph. It is moored at a marina and there's a little growth on the hull...but would this make a real difference? The engine is 2007 still under warranty and sounds and runs fine. it has a standard 17" prop. Would going to a slightly larger prop make that much difference / damage the engine?
Cheers for any thoughts.