I bout a boat with a 1965 Mercury 90hp Merc900 engine on it. I replaced the impeller in the lower unit and put it all back together,the motor cranked right up after I hooked up the water ears and turned the water on.It runs good but when I took it to the lake the other day and gave it a full throttle,it would oniy go about 10 to 15 mph.I think this engine should run a little faster than that. It's on a 1965 Crosby Runabout tri-hull boat.Any help or suggestions?
