I have the above motor with about 25 hours on it. Its on a 1800 F/S Astro and I can only get about 4700 rpms from it. IS it the prop or does it need adjusting, boat runs about 55 with three people and gear and a full load of fuel.

Please HELP!!! is there anything wrong with it or is this max rpms for the boat?

Is it the original prop? If so, what did the engine tach when it was running good? You should be taching somewhere in the mid 5000's at WOT. Is this carbureted? How does it idle? Do you have spark on all cylinders? Do a compression test on all cylinders. What do the spark plugs look like?