hi all,

I'm doing some basic maintenance (changing spark plugs, greasing prop
shaft, changing gear oil and maybe changing the impeller)on my first
boat and have these questions. Any advice is appreciated. thanks in
advance.

outboard is a 83 v4 evinrude 90 hp.

1. upon pulling out the spark plug from cylinder 1, I saw some white
powder around the outer area where the plug sits, is this normal or is
it from overheat? the ceramic around the center electrode is the
normal grey color but the top of thread surrounding the ceramic shows
black flaky deposits, plus the threads are a little sooty with oil,
does that mean it's running too rich? it has vro.

cylinder 2 to 4 don't have the white powder in the outer area. Plus,
the original paint around head gasket on #1 and #3 is completely gone
and shows a little bit of corrosion while #2 and #4 still have very
good paint. is this overheat indication? why the difference bwtn the
two banks?

2. when greasing the prop shaft, should I grease the area behind the
thrust washer (it looks like a bearing, I think that's the carrier)

3. the gear oil drain plug is frozen, any advice on how to loosen it.
I already tried lots of wd40. if I use a soldering torch(the kind for
soldering copper pipes) will it damage anything?

4. any tips/advice on what to do or not do when attempting your first
impeller change. I read it's to screw up the rod or something.

5. the guy who sold me the boat said the shop changed the engine oil
on it. I thought 2 strokes only take oil from premix or the oil
injection. any one know where is the oil located(generally), my
service manual didn't mention anything on that. do 2 stroke have oil
filter as well?

sorry for the many questions. thanks in advance.

s o