Capt John wrote:

Generally speaking, they reccomend straight weight oils because it
tends to hold up better under constant heavy loads.

Untrue & folklore. 10W-anynumber is 10W oil with vicosity improvers
that preserve its film integrity up to the temperatures that 30W oil
would otherwise be required for the same film strength.

Their's not much of
a differance, but the manufacturer takes the safe rout by reccomending
this.

Untrue and folklore. Oil molecules act like little balls
(oversimplification) and 10W "balls" are smaller than 30W "balls", if
you will. You may think of it as pouring liquid ball bearings into
your engine. The fooken engine & its clearances have been designed for
a specific "size." The difference btw 10W30 & 30W is night and day
from this standpoint. As another pointed out, this kind of boat engine
runs in a narrow temp range and at generally steady loads. Today's
engineers & designers may commit many stupid and even idiotic things,
but they are not yet so lame as to "take the safe route by recommending
this" - there is a very good reason for it.

Marine oils tend to have additional compounds in them that help
prevent rust inside the block,

Folklore & a little creative marketing at times.

but I've never seen it make a
differance. On your flame arrestor, anything from diswashing liquid to
engine degreaser works, I always preferred the degreaser myself.

A solvent is a solvent, and these are not, despite the fact they may
work somewhat. Gasoline does as well or better and is a solvent. So
is xylene, and others, from Home Depot. Any of them plus a toothbrush
will work better & faster than those 2 non-solvents. Mineral spirits
is not worth a crap as a carbon dissolver/cleaner.

On oil
pressure, general rule of thumb, 10 pounds of oil pressure for every
1000 RPM's,

Dangerous folklore. Modern engines have various degrees of oil
pressure regulation.

lower than that, you've probably got a problem.

If he has 10 psi at 1,000 rpm (not), he/she sure has a big fooken
problem. :-)

I'm not
sure about your grease other than marine grade (water resistant) is the
way to go.

White lithium is the general standard used everywhere in small marine
use. To be sure something different isn't required or for warranty CYA
purposes, RTFM rather than ask on usenet.