This is on a 1999 starcraft with alpha 1 gen 2 sterndrive. Well, had the boat out for the first full day. Got the trim fixed, water in the locker fixed, and control box fixed. Ran great all day with temp in the mid range pulling a 3 person tube. Wind died down later that night, so I opened it up to the trailer. Pulled 4500 rpm at 40 mph with trim all the way down using 91 octane. Then I started getting a knock sound that got louder and louder until I shut it down. It was a solid loud knock but couldn't really tell if it was from engine or drive( gimble bearing?) Sounded like something was rubbing or hitting something else. In neutral it was still making noise and increased with rpm increase. Oil was good, temp good, and it started back up fine but with knock. I got pulled back in. This morning it sounded like it knocked for just a bit and then went away. It idled smooth with no hickups using muffs, no leaks and nothing looks melted. Put in forward and reverse and it sounded normal. I pulled one spark plug and it looked good. Something got warm when running full throttle. With muffs on, water was coming out underneath the upper drive. What should I check?
