Re: loud engine knock 350 merc w/alfa1
Don't know if this is your problem or not but I recently had a simaliar prob. I found that the flywheel cover on my 350 some how was bent and hitting the flywheel. It was making a mettalic clanking noise but did not inhibit the performance of the boat. Ran the boat out of the water w/flush muffs on and could not even hear it outside the boat, but inside, on right, towards rear of engine it was fairly loud. The cover is located behind the oil pan on the front of the bell housing. You can check it by removing the bolts that hold on the cover and dropping it down and re-starting. If sound goes away then thats your problem. hope this helps..
