Optimax rattling noise

"I have a 2001 Optimax 225, an

"I have a 2001 Optimax 225, and it was making a rattling noise for a couple of weeks. The other day, while I was on plane, I heard a loud bang and came right down off plane. I put the engine in neutral, and gave it some gas, I could hear the noise, so at this point I ASSumed the problem was not in the lower unit, but the engine itself. I got towed in, and when I got home, I spun the prop with it in neutral and it felt and sounded fine. I put the boat in gear and it engaged the prop. I couldnt spin it at all in gear, which is what I expected. So, all of this confirmed my suspicion that the problem was in the engine itself. I Stripped everything off the block and exposed the pistons, rods, caps, etc. It all looked fine, so I spun the engine by hand and watched the pistons and rods, and they all worked fine. So, I put it all back together and fired it up in the garage and there was that noise again. Where should I be looking?"

"One more thing. The water str

"One more thing. The water stream coming from the engine is not as strong as it normally is. Its a steady stream, but it comes out in an arc, rather than a straight line. I was looking at the service manual, and saw that the water impeller is actually on top of the lower unit, so again I am ASSuming the shaft that comes out of the lower unit is turning even in neutral? Can the problem be in that mid section between the engine and lower unit? What goes on in there?"

"Did you check the compression

"Did you check the compression? Watch this clip, it may help you.
http://www.meegsonline.com/tmd/TMDsVideoChronicle.wmv"