but can't find any solid data on it in searches. Whats the average
lifespan in hours of an outboard....say a 50hp and a 90hp etc 4
stroke?

example ran everyday not hard but cruising speed. I know theres alot
of ifs etc but somewhere there has to be some data from fishermen,
charter, etc...

I couldn't begin to touch that one - particularly for 4 strokes.

I do know the 44 cubic inch Mercury 2-stroke 45-50hp 4 cylinder has an
ungodly lifespan though. Likely to outlive it's owner. LOL

-W

"shawn" wrote in message
om...
but can't find any solid data on it in searches. Whats the average
lifespan in hours of an outboard....say a 50hp and a 90hp etc 4
stroke?

example ran everyday not hard but cruising speed. I know theres alot
of ifs etc but somewhere there has to be some data from fishermen,
charter, etc...

I reflect on this because after we move, I plan on powering a new party
barge with one of those critters. I plan on going in and giving it an
overhaul, knowing full well when I close it back up, I'll likely be dead
before anyone ever opens it up again. Strange feeling indeed.

-W


"Clams Canino" wrote in message
news:BT_gb.715660$uu5.117719@sccrnsc04...

I do know the 44 cubic inch Mercury 2-stroke 45-50hp 4 cylinder has an
ungodly lifespan though. Likely to outlive it's owner. LOL

Just guessing but since it is a toy (in the sense of "he who has the
most toys wins") the lifespan will probably be about 3 hours short of
the return to the dock on a very long lake.

On 8 Oct 2003 13:13:41 -0700, (shawn) wrote:

but can't find any solid data on it in searches. Whats the average
lifespan in hours of an outboard....say a 50hp and a 90hp etc 4
stroke?

example ran everyday not hard but cruising speed. I know theres alot
of ifs etc but somewhere there has to be some data from fishermen,
charter, etc...

For the most part they will last forever if treated right. This assumes
you burn good quality gas (with no water) and good quality oil, change the
plugs when you should, winterize when you should, change the water pump when
you should, and don't let the carbs or fuel injectors clog up from setting
w/ fuel in them.

If you don't do the above, may not last a season or two.
If you do, it may still go down just due to a flaw in the metal or some
electrical problem causing it to run lean.
These are the chances you take with any engine.

Just like a car. Some last forever if treated right. Others go out quick
for no reason.


--
Tony
My boats and autos - http://t.thomas.home.mchsi.com



"shawn" wrote in message
om...
but can't find any solid data on it in searches. Whats the average
lifespan in hours of an outboard....say a 50hp and a 90hp etc 4
stroke?

example ran everyday not hard but cruising speed. I know theres alot
of ifs etc but somewhere there has to be some data from fishermen,
charter, etc...

gemmilljim@hotmail,com wrote in message . ..
Just guessing but since it is a toy (in the sense of "he who has the
most toys wins") the lifespan will probably be about 3 hours short of
the return to the dock on a very long lake.

I believe this is the right answer...

Tony Thomas wrote:
For the most part they will last forever if treated right. This assumes
you burn good quality gas (with no water) and good quality oil, change the
plugs when you should, winterize when you should, change the water pump when
you should, and don't let the carbs or fuel injectors clog up from setting
w/ fuel in them.

If you don't do the above, may not last a season or two.
If you do, it may still go down just due to a flaw in the metal or some
electrical problem causing it to run lean.
These are the chances you take with any engine.

Just like a car. Some last forever if treated right. Others go out quick
for no reason.



Trouble is neither cars nor any other mechanical thing seems to last
all that long & 2 stroke OBs are at the bottom of the heap:-)

OBs particularly 2 strokes, despite their pricing are essentially throw
away items. Rarely do they actually "wear" out they succumb to their
inherent design faults long before that:-) About 600 hours is the
accepted number around here, but in freshwater with luck it might be a
bit longer.

The OB dealers all have a log of spruiking stories about this or that
OB that had 3000 hours on it etc. But they leave out that it was a
commercial fisher who used it a few hours every day, never really
stressed it & wasn't too concerned about how much they spend on
"service". Of all things & a classic example how the spruiker dealers
will grasp at any straw they can, "was" a pair of 150HP Fichts on an
abalone dive boat down here that were claimed to have over 3000 hrs on
them, probably true but little comfort to 1 in 5 owners who suffered
almost instantaneous (well the cheques got cleared first) Ficht failure.

Some of the suggested reasons for these dealer delight anomalies;

(a) OBs a are mostly raw water cooled into aluminium (only know of one
that isn't:-)) which means they are corroding from the getgo. Every time
the motor is stopped the powerhead is designed to drain the water
(usually salt).
The powerhead is hot at this time so any residual water evaporates off
the surfaces leaving a salt buildup, yes a freshwater flush immediately
can help but it's not much use an hour or two later when you get home.
Any salt left as a hard deposit will not dissolve with water & it takes
on the characteristics of concrete.
As the motor ages in years not running hours, these buildups don't need
to actually block anything, just create little hot spots which of course
are them self sustaining, building more salt every time the motor stops.
Hot spots are what kill engines of any type on the ....... spot?? They
occur in the head region which leads to detonation/pre-ignition = some
flat forehead dealer telling you it's your fault for not using their 3
times the price TCW3.
The mythical dealer stories are probably partly true because a motor
used every day doesn't buildup deposits any more & maybe can avoid it
almost all together.

(b) The 2 strokes have a significant flaw in their cooling of the
piston, there is none! All 4 strokes carry lots of heat out of the
piston with oil, proper engines have oil spraying up under the piston
all the time for this very purpose. Crankcase transferred 2 strokes have
no effective cooling of the piston & more importantly the rings. This
usually limits to size of 2 stroke pistons to about 500cc per cyl,
(although those Ficht idiots are about to try for more, dumb dumb
dumb!!) because as the piston diam. increases the surface area subject
to heat input increases by the sq.of the radius, but the length of the
rings trying to transfer that heat into the comparatively cool bore only
increases linearly (the circumference just goes up by 3.14).
The end result over time is that the oil gets baked behind the rings so
they no longer flex in & out as the pistons move & then blowby can
occur, unlike other engines you won't see anything because it just
recirculates through the transfer ports, but then piston heat builds
even more till there is a sufficiently hot enough spot = same answer
detonation/pre-ignition = some flat forehead dealer telling you it's
your fault for not using their 3 times the price TCW3.

Better concede that Clam's engines are pretty good in this department
(before "he" has a complete detonation leading to a seizure;-)), they
have lots of tiny diam pistons, so piston/ring temp has a better chance
& just as he says they do have very good service lives, don't know if
the early OB designers were that much cleverer than current or just luck
but whatever, they're a good blind blind proof of the reasoning.

(c) The fueling is problematic, they usually have individual fueling
for each cyl, this means that any problem in one will have no impact of
any others. So even a slight main jet blockage, or something as low
delivery pressure to the top cyl leads to the subject cyl running on a
lean mixture, but you won't notice because the others are fine.
Result improper combustion patterns from the lean mixture & hot spots =
same answer detonation/pre-ignition = some flat forehead dealer telling
you it's your fault for not using their 3 times the price TCW3.

(d) The oiling can be an issue particularly with OMC VRO engines, yes
even if they change the name. Over time it leaks fuel into the oil side
of the pump, the alarms won't/can't warn you so it's very dangerous in
any OMC engine over a couple of years old, obviously as the oil slowly
gets cut back this generates heat leading to hot spots = same answer
detonation/pre-ignition = some flat forehead dealer telling you it's
your fault for not using their 3 times the price TCW3.
Be very careful here they'll even send the rebuilt engine back out with
the same VRO pump on it!!! Damn they're stupid or dishonest but mostly both.

(e) The transmissions are the next worry, they're very short term. In
theory the bearings & gears shouldn't even carry the HP put through
them, but because it's to a prop in nice soft water & immersed in cold
water with an aluminium case that can carry the heat away they get away
with it; for a while. The system is supposed to be sealed with a bubble
of air in the top to allow for expansion as it heats & then cools
quickly in cold water, after very little use that bubble of air gets
squeezed out past the drive shaft seal, so as it cools it sucks water in
& well OK no detonation this time but it's still the end of your boating
& bank account for a while. The other problem is the roof of the gearbox
is constantly blasted with very hot salt water laden exhaust, this
accelerates what is already a sad corrosion situation such that even if
you manage to make the internals last (keep the water out) the case
dies. Usually the gearbox roof gets porous, no actual put your finger in
hole but the aluminium just dissolves.

So accept it's a pleasure craft engine which is not designed to last
even by auto engine standards.

K


& Harry's lie for the day is one of my personal favourites, given he
can't even join any of the sailing nor navigation threads for lack of
knowledge, what a sad little sausage he is;

Have you ever sailed from San Francisco to Hawaii? I have.
Have you ever rounded Cape Horn? I have, twice.
Have you ever transited the Panama Canal? I have.
Have you owned more than 20 boats in your lifetime? I have.
Have you ever sailed large boats competitively? I have.
Have you ever been hundreds of miles from land in a powerboat under your
command? I have.

Okay, I thought about what you wrote until it weirded me out.

I think I was right where you were at when you wrote, "strange feeling
indeed". It is.

"Clams Canino" wrote in message
news:c__gb.706590$YN5.575735@sccrnsc01...
I reflect on this because after we move, I plan on powering a new party
barge with one of those critters. I plan on going in and giving it an
overhaul, knowing full well when I close it back up, I'll likely be dead
before anyone ever opens it up again. Strange feeling indeed.

-W


"Clams Canino" wrote in message
news:BT_gb.715660$uu5.117719@sccrnsc04...

I do know the 44 cubic inch Mercury 2-stroke 45-50hp 4 cylinder has an
ungodly lifespan though. Likely to outlive it's owner. LOL

"K Smith" wrote in message
-

Better concede that Clam's engines are pretty good in this department
(before "he" has a complete detonation leading to a seizure;-)), they
have lots of tiny diam pistons, so piston/ring temp has a better chance
& just as he says they do have very good service lives, don't know if
the early OB designers were that much cleverer than current or just luck
but whatever, they're a good blind blind proof of the reasoning.

Smart girl (this time)

I primarily deal with the 99ci six (16.5 ci per cylinder) and those motors
do get "coking issues" around the rings if you don't use a decent quality
*ashless* oil. And despite the downsides - I do recommend using a can of
Mercury "Power Tune" as directed, once a year, to try to keep those rings as
clean as possible. I know it washes all the oil out too - but it's only for
a moment. They have a long service life - but you do have to follow all "the
rules".

The one I called a true "lifetime motor" was the 44ci inline four. At only
11ci per cylinder, it's indeed a nice small piston. The real secret of those
though is that the burn efficiancy is lower becasue they never *got* the
"new design" piston. So even though they make only 1hp per cubic inch - they
are running a lot cooler than the 99ci making almost 1.5hp per cubic inch.
You'll see those little 45 or 50hp Mercs running around everywhere - to this
day. They are a post WW-2 design that survived almost intact till the very
late 90's when EPA regs kinda made them look bad - LOL. I picked up a 1958
unit (because it looks cool) and plan to use that for a barge pusher.


-W

It's a 1958, only reason I'm going in is that it sat too long improperly
stored and seized.
The imlications weird me out too. Now think about this........ all that
stuff works in the *dark* till someone splits the cases. We just visualise
it all with light.

-W

"Paul" wrote in message
le.rogers.com...
Okay, I thought about what you wrote until it weirded me out.

I think I was right where you were at when you wrote, "strange feeling
indeed". It is.

"Clams Canino" wrote in message
news:c__gb.706590$YN5.575735@sccrnsc01...
I reflect on this because after we move, I plan on powering a new party
barge with one of those critters. I plan on going in and giving it an
overhaul, knowing full well when I close it back up, I'll likely be dead
before anyone ever opens it up again. Strange feeling indeed.

-W


"Clams Canino" wrote in message
news:BT_gb.715660$uu5.117719@sccrnsc04...

I do know the 44 cubic inch Mercury 2-stroke 45-50hp 4 cylinder has an
ungodly lifespan though. Likely to outlive it's owner. LOL