How to assess the value and reliability of an old but rebuilt outboard
 

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?

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

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

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?

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

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

Get in touch with Clams Camino here...he's the ranking old Merc expert...

I'd say that even if your 30 year old engine is running, its value is
marginal, if, by value, you mean what someone would be willing to pay
for it in a reasonable period of time.


--
We today have a president of the United States who looks like he is the
son of Howdy Doody or Alfred E. Newman, who isn't smarter than either of
them, who is arrogant about his ignorance, who is reckless and
incompetent, and whose backers are turning the United States into a pariah.

What, me worry?

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

"Sailman" wrote in message
om...
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?

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

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

I once bought a boat with a 115 Merc attached, I think it was about
a 1984 engine. The engine ran fine my first season. When I put her in
the water on the second season it worked for 10 minutes then the
shaft running from the engine to the prop broke. From everything
I could find out it seems we would have had to take the engine
compleatly apart to fix the shaft.

Anyway, here's my point/advise: Even if compression & all else looks
good and it runs strong - any engine can break in a major way. And older
engines are more likely to break with major problems. ~ As for the
rebuild: as another poster said, you don't really know what was rebuilt.
Even if they repaired everything else, some one major part (like the shaft
in my engine) could still go.

Another way to consider this: Say something major DID break. Something
big enough that the cost to repair was not worth it. Then what would the
boat be worth?

Good luck.

If the drive shaft broke all you had to do was drop the lower-unit Gary,
easy fix.
Next time ask me 1st. :)

Now on the the older 115. With the exception of perhaps the 44ci four, that
inline six was the motor that made Mercury the name it is today. If it was
correctly rebuilt / re-ringed I'd not be afraid of it **at all**.

That year has a CDI ignition with a distributor. Check the wireing
(particularly the three coming out of the distributor body) for signs of
dry-rot (common but not insurmountable problem).

Ask to water test the boat with the owner, if it's been sitting and needs a
carb cleaning - that will show up in the water more so than on the muffs.

When you get it, verify the max advance on the timing is 21 degrees (not
more) - and use mid-grade gas.

The main problem with the old inlines is finding a competant mechanic to
service it that won't gouge you. If you plan on working on it yourself, get
the manual and become one with it.

If you live within 100 miles of the SC / GA border on I-85, you're safe - I
can service it.

If you ever need parts for it - talk to me 1st - I have the largest
inventory of used Tower of Power parts that I know of anywhere.

-W

"Gary Warner" wrote in message
...

"Sailman" wrote in message
om...
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?

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

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

I once bought a boat with a 115 Merc attached, I think it was about
a 1984 engine. The engine ran fine my first season. When I put her in
the water on the second season it worked for 10 minutes then the
shaft running from the engine to the prop broke. From everything
I could find out it seems we would have had to take the engine
compleatly apart to fix the shaft.

Anyway, here's my point/advise: Even if compression & all else looks
good and it runs strong - any engine can break in a major way. And older
engines are more likely to break with major problems. ~ As for the
rebuild: as another poster said, you don't really know what was rebuilt.
Even if they repaired everything else, some one major part (like the shaft
in my engine) could still go.

Another way to consider this: Say something major DID break. Something
big enough that the cost to repair was not worth it. Then what would the
boat be worth?

Good luck.

On Wed, 29 Sep 2004 18:39:02 GMT, "Clams Canino"
wrote:


If you plan on working on it yourself, get the manual and become one with it.

That's true of anything of vintage.

Good advice.

OOOOOOOOOHHHHHHHMMMMMMMMMMMM..........

All the best,

Tom
--------------

"What the hell's the deal with this newsgroup...
is there a computer terminal in the day room of
some looney bin somewhere?"

Bilgeman - circa 2004

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?

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

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

I would suggest a sea/water trial is essential in this case, with the
engine starting from cold. Pay attention to to noises and vibration
throughout the throttle range, watch the temp gauge like a hawk, and a
good few stop, starts during the trial, as well a good few forward
reverse shifts. After the test, drain the lower case oil completely
and check for water and debris. Also try to determine if the prop
pitch suites the boat during the trial.

Good Luck.