I apologize in advance for being off topic but here goes. The subject is a 200 hp Mercury outboard.It developed a really bad knock at idle but ran great a speed.I continued to run it because of a tight tournament schedule It took me quite a while to figure it out but it ended up being a loose flywheel. Anyway,I tightened it up and it was ok for a while but came loose again.This continued to happen quite frequently.The flywheel is on the tapered keyed top end of the crank.I bought a new flywheel,washer and nut,coated everything with red Loc Tite and the problem disappeared for a year or so but now it's back.Apparently the taper on the end of the crank is somewhat compromised. The question....Is there any type of compound or other method I could use to tighten this connection? Boat guys have nothing to add except a new crank.I know there are a bunch of brilliants minds on here and am hoping someone can help. Thanks!