O.K. guys, I have a 1979 90hp merc. A tower of power as they call them. On my last trip on the river I heard several noises and a couple good jerks at the motor. I started the motor today at the house and it definetley has a noise in it. From my experience it sounds like it's probably a rod bearing. Not sure how to tell without tearing it down. The noise comes and goes at different rpm's like a bearing in a car engine would do. When I throttle up the noise goes away until the motor reaches the desired rpm, then the noise is back. I know you can't hear it from there. I am mechanically inclined and have built a couple car engines. My question is this? It's an old motor, is it worth the effort and the money to go thru it or should I just start looking for another engine? Compression was 145, 185,185,185,185, and 185. It's been that way for two years and @ 800miles on the water. I also have a complete 78 115hp that I've robbed of a few parts. The 115 had the same noise so I was scared to run it. What do you think? Where would a fellow get a bearing and gasket set?