On 29 Sep 2004 08:49:11 -0700, (Sailman) wrote:

I am considering buying a boat with an old (c. 1975) 115hp Mercury
outboard. According to the seller, it was rebuilt about 300 hours ago
and runs great. Assuming the basic checks came back fine
(compression, lower unit oil, etc.) and that it was rebuilt by a
reputable place, is an old but recently rebuilt outboard a good idea?
Put another way, is a 300 hour rebuilt engine comparable to any other
300 hour rebuilt engine, or does the old age add significant negative
issues?

Depends on what was "rebuilt". You have to be cautious when you come
across this term because it can mean a lot of different things
depending on who you are talking to. Is replacing a head
"rebuilding"? Replacing plugs, wires, spark coils? I would determine
exactly what was changed, replaced or refurbished. Any repair that
does not have a receipt attached to it is suspect. Nothing personal
in that - could be the most honest person on the face of the earth
selling the engine - no receipt, no repair.

Another thing is hours - over how much time was that 300 hours
developed? Was it done over one season, two, five, twelve?

Parts can be a problem. Engine repair guys around here don't accept
engines older than 1987. I know of one who does engines back to 1975,
but reluctantly.

Also, any guess as to the value of such an outboard?

That is relative value. If you go here

http://www.nadaguides.com/Values/Val...wPr=0&wPg=1027

it will give you an idea of what the motor is worth.

Finally, is there some natural limit to the numbe of times you can do
a major rebuild on an outboard?

Again, what's major? There are only so many times a blocks and heads
can be honed, bored, repolished, etc, if that is what you mean. More
than once, I would be looking for a new engine.

But that's me.

Good luck.

Take care.

Tom

"The beatings will stop when morale improves."
E. Teach, 1717