I'm getting ready to change the head gasket on my 50 HP Evinrude (1993).
#30 in upper Cyl, #120 or so in the lower one. I don't see any visible
signs of stuff squirting out the head gasket, so I am of the assumption
it's an internal breach with the water jacket as evidenced by the rust on
the sparkplug.

I got the Clymer book from the library, however that claims that you are
supposed to put a bead of some goop or other on the head gasket, and then
re-assemble, and torque the bolts down to 18-20 foot lbs. Could this be
right? I can nearly achieve 18 foot pounds with my fingers! I've never
seen an situation where the head bolts weren't torqued REALLY tight. I know
it's a small motor, but if someone could enlighten me as to why they
shouldn't be torqued down closer to 50 lbs (other than obviously the book
says don't.) Another thing, I was told in some applications you should get
the motor hot, and then re-torque the bolts again, and run it for some
period of time, and repeat the procedure. Anyone know anything about that?
That process is missing from the book as well.

I am unclear as to why the head gasket blew in the first place, there is
plenty of water coming out the telltale, and the engine alarm never went
off. A friend suggested I check the tightness of the head bolts, and they
were VERY loose, particularly the bolts on the top Cyl, the one with #30 of
pressure.

Thanks.

-BrianDP