Full test this morning. Boat did very well. Ran it about five miles or so. Very dry run, speed seemed OK, however I didn't bring anything to measure it. Specs say with a 9.9 it should run 21-23 mph, which is OK for a boat that light.
While the cooling problem with the motor was solved, I ran into another problem. If the motor idled for 3-4 minutes when I opened the throttle it would stall and seemed to be flooded on restart attempt. Had to drain the bowl to get it to go. It was actually doing that before I took it off the sailboat. At that time I thought it was the normal jet problem with these small motors, now, since I thoroughly cleaned the carb, I think it might be a float/needle valve issue. Got to get that fixed.
Next I go out with a tach and speedometer to see if a can handle a little more pitch and get some more speed. Got a 9.25 x 7, maybe I can handle an 8. Also considering converting it to a 15HP. Displacement is there think it is just a matter of carb parts.
A couple in the water.