"TJ" wrote in message
...
This is a long post, but bear with me, I will eventually get to the point.
There's just a lot of background to fill you in on.

I have a '64 9.5 HP Johnson outboard that gets used heavily on a 14-ft.
aluminum boat during a one week vacation each year on the St. Lawrence
Seaway. The rest of the time it sits idle, hanging on a stand or on a
wall, waiting for my next fishing opportunity. I originally got it for
free in 1986 from my sister-in-law's father, with a cracked block. By the
time I was done with her, I'd purchased a used block, one new piston and
rings, new gaskets, and a new crankshaft. It ran like a top, often
starting on the third or fourth pull when I got it out of storage, and
almost always on the first one until I put it back in storage. All it ever
needed was a periodic changing of the lower unit oil, and some points
maintenance.

Then came last year, and the honeymoon was over. It was my own fault, too.
One day while trying to launch by myself on a rather windy day, the wind
blew me back onto some rocks before I could do anything about it. That
tore up the rubber shock bushing in the prop. Naturally, the local OMC
dealer, about an hour away, was the only place to get one. According to a
book I have, the original prop was an 8 1/8 x 8 inch. All the dealer had
that would fit was an 8 1/4 x 9 inch. It was either that or ruin vacation,
so I bought it.

But that's not all that happened. I put the new prop on and it seemed to
work ok, despite being "bigger" than the original, but it wasn't really
the kind of day when one can test performance. The next day I was out
fishing with my mother, when the water pump impeller decided to give up.
It was at the most inconvenient time, too (Is there a GOOD time for
it???) - when I had to keep running it to get out of the way of
God-knows-how-many-tons of freighter. (Hey, there's nice smallmouths in
that shipping channel, but you just don't argue with one of those guys.) I
got out of the way, but I had to run the ol' Johnson until the pistons
seized to do it.

That made me physically ill. I was sure the ol' girl was a goner, but
after being towed in, allowing it to cool, checking things like the points
and compression, I tried it and it started! Ran nice and smooth, too - for
what little time I let it. Then it was back off, pull the lower unit
apart, and another two-hour round trip to the OMC dealer for an impeller.
I put it back together and ran it the rest of the vacation on our second
boat - the one my mother *doesn't* use. (Trust me - I didn't want any more
breakdowns with her in the boat.) It ran fine once it started, but now it
would take at least three or four pulls to start it every time, and
sometimes you had to choke it in the middle of the day - unheard of
before. Didn't quite have the zip it had before, either - but I put most
of that to the different boat. I was just so overjoyed that it even ran
that I wasn't about to complain.

Then came this year. When I brought it out of storage, it took 12-15 pulls
to get it to start the first time. Every time thereafter it took at least
three. The power wasn't there, either. It was only about 3/4 of what it
was before. It still ran smoothly, though, and if I hadn't known what it
was capable of, I might not have thought anything was wrong - until the
last day. On that one, it started misfiring, and it ran like it was half a
motor.

So I'm thinking some major work is in order this winter. I suspect a
modest crankcase leak. I'm considering new rings, head gasket, and
crankshaft seals. New plug wires probably wouldn't be a bad idea, either.
They're still the originals. New plugs, too - those plugs are the ones
that went through the heat stroke. (I think that last day misfiring could
well be a plug going bad.) I toyed with the idea of new bearings, but I
think that if they were bad that would have shown up catastrophically
during this year's vacation.

I have two questions. Is there anything else I should be looking at? And,
how much of the poorer performance could be attributed to the "bigger"
prop? (meaning, should I buy one closer to original specs?)

TJ

My thought would be that seizing it damaged the piston/cylinder and possibly
the seals as well. Pull the top end and take a look at the cylinder wall to
see if you can get by with a piston/rings or if you need a whole new top
end. It's not unusual for seized 2 strokes to run again after cooling down
but they seldom are ever the same. When's the last time you had replaced
the impeller?