Anyone want to take a shot an an overheating problem?
 

I have a 2002 4 stroke 60 HP Merc.
I took it in for the 500 hr and everything was fine before I took it in. $437
later (a new impeller, plugs and an oil change) I have an overheating problem
when I go over 4000 RPM.
I get Mercury involved and they say go to another dealer. $350 later (lots of
easter egging around, a new thermostat, a housing THEY BROKE and another
impeller) and I am still overheating. I hooked up a guage and it is 4PSI until
the thermostat opens then it is more like 2PSI. RPMs don't seem to change it
much and whenever I get much over 3000 RPM I see the temp climbing. At 4000 it
is very hot and the beeper goes off.
I am collecting a white pasty substance around the thermostat that I think is a
result of evaporating salt water since the flow is so low. Even when it is all
flushed out I am still having the problem.

Anyone want to take a shot an an overheating problem?
 

I have a 2002 4 stroke 60 HP Merc.
I took it in for the 500 hr and everything was fine before I took it in. $437
later (a new impeller, plugs and an oil change) I have an overheating problem
when I go over 4000 RPM.
I get Mercury involved and they say go to another dealer. $350 later (lots of
easter egging around, a new thermostat, a housing THEY BROKE and another
impeller) and I am still overheating. I hooked up a guage and it is 4PSI
until
the thermostat opens then it is more like 2PSI. RPMs don't seem to change it
much and whenever I get much over 3000 RPM I see the temp climbing. At 4000
it
is very hot and the beeper goes off.
I am collecting a white pasty substance around the thermostat that I think is
a
result of evaporating salt water since the flow is so low. Even when it is
all
flushed out I am still having the problem.


I know you have been around boats a while.
While this can be tricky to trace, basic troubleshooting should steer you to a
solution.
One thing I would ask is: Was the engine overheated?
I have seen the grommet where the water tube goes into the powerhead adapter
melt. That would limit the flow to the powerhead.
When they changed the impeller did they change all the gaskets?


BR

Anyone want to take a shot an an overheating problem?
 

I don't think it ever got over 200 degrees. I have only heard the beeper a
couple times, mostly just to prove the high guage reading is real (they have
tried to tell me my guage is wrong)
If I shut it down to an idle immediately the beeper stops.
They said they pulled the lower end shroud and inspected the supply pipe and
gasket in that $300 easter egg hunt although I wouldn't bet on anything at this
point.
I watched him do the second impeller and they installed the complete kit with
the plates and grommets. The removed impeller looks brand new, as it should be
since it was, but the plate may not have been replaced the first time.
My neighbor has a motor similar to mine and I am thinking about swapping the
foot with him to cut this problerm in half but that is a lot to ask.

Anyone want to take a shot an an overheating problem?
 

You may have given us a clue, with the low psi. Where did you take the
reading? top of the block? before or after the thermostat? Also, what is
your water source? Are you using the clamp on "ears" or is the foot
submerged? I'm not sure of the spec for your particular motor (my 200hp 2
stroke climbs up to 10-15 psi at idle and 20-25 at 4-5000rpms) but some
motors are half that. No matter, 2-4 psi taken properly at 2000-4000rpm
sounds way too low. Assuming the impeller is correct and installed
correctly, something in the line is leaking and preventing pressure from
building.

On another note, Are the new plugs of the same heat range? A "hotter" plug
could be the culprit.
LD

"Greg" wrote in message
...
I have a 2002 4 stroke 60 HP Merc.
I took it in for the 500 hr and everything was fine before I took it in.
$437
later (a new impeller, plugs and an oil change) I have an overheating
problem
when I go over 4000 RPM.
I get Mercury involved and they say go to another dealer. $350 later (lots
of
easter egging around, a new thermostat, a housing THEY BROKE and another
impeller) and I am still overheating. I hooked up a guage and it is 4PSI
until
the thermostat opens then it is more like 2PSI. RPMs don't seem to change
it
much and whenever I get much over 3000 RPM I see the temp climbing. At
4000 it
is very hot and the beeper goes off.
I am collecting a white pasty substance around the thermostat that I think
is a
result of evaporating salt water since the flow is so low. Even when it is
all
flushed out I am still having the problem.

Anyone want to take a shot an an overheating problem?
 

I have the guage in the bottom of the water manifold where they feed to the
fuel coolers and eventually out the pee hole.
Thelflex suggests that as one of the points. This is all with the boat in the
water running. It will not fail on a trailer. The boat needs to be pushing
water to be running hard enough to overheat.
With the thermostat out it acts similar at speed, overhreating around 4000, but
up to about 2000 RPM this thing won't even get hot enough to make the computer
happy (100-110 degrees, without the thermostat). It runs like a car in "limp
home mode".
I only tried that once, just to see if there reallty was TWO bad thermostats.
(I am on #3 now in the $300 hunt).
I really think this is just not pumping enough water and under a load it
overloads the ability to cool. Simple huh?
You can see why I really want to swap the whole damned foot.

Anyone want to take a shot an an overheating problem?
 

"Greg" wrote in message
...
I have a 2002 4 stroke 60 HP Merc.
I took it in for the 500 hr and everything was fine before I took it in.
$437
later (a new impeller, plugs and an oil change) I have an overheating
problem
when I go over 4000 RPM.
I get Mercury involved and they say go to another dealer. $350 later (lots
of
easter egging around, a new thermostat, a housing THEY BROKE and another
impeller) and I am still overheating. I hooked up a guage and it is 4PSI
until
the thermostat opens then it is more like 2PSI. RPMs don't seem to change
it
much and whenever I get much over 3000 RPM I see the temp climbing. At
4000 it
is very hot and the beeper goes off.
I am collecting a white pasty substance around the thermostat that I think
is a
result of evaporating salt water since the flow is so low. Even when it is
all
flushed out I am still having the problem.

Blown head gasket. Do a compression test.

Anyone want to take a shot an an overheating problem?
 

Blown head gasket. Do a compression test.

How does that lower water pressure?

We did look at the plugs and they all seem to be burning about the same, no
water in the oil and no pulses in the water jacket. Since this pressure ends up
below 60" of water (about 2PSI) I have been able to watch this with a precision
0-80 In/H2o guage. If I had a water to combustion leak I would expect to see
the guage bumping when that cylinder fired.
We have thought about a head gasket but I don't think they checked. I will ask.
Thanks

Anyone want to take a shot an an overheating problem?
 

I guess, if you haven't already, find out what the recommended pressure is.
I located my info for Mercurys (with a "Mercury" gauge). The lowest is
"6-12psi" for 50/60/65/70 3 cyl and the highest is "15-25psi" for a lot of
engines, most all the V-6's and all #'s are at "above 5000rpm".
I'm with you---2-4 psi isn't enough. A phone call to any dealer service
dept should get you the specs. My bet is either a leak or restriction
between the pump and the block. 'Course, it could also be a blockage before
the pump. It's easy enough to change the foot which, like you said, would
confirm or eliminate "half" the potential problems.
Good luck.
LD

"Greg" wrote in message
...
I have the guage in the bottom of the water manifold where they feed to
the
fuel coolers and eventually out the pee hole.
Thelflex suggests that as one of the points. This is all with the boat in
the
water running. It will not fail on a trailer. The boat needs to be pushing
water to be running hard enough to overheat.
With the thermostat out it acts similar at speed, overhreating around
4000, but
up to about 2000 RPM this thing won't even get hot enough to make the
computer
happy (100-110 degrees, without the thermostat). It runs like a car in
"limp
home mode".
I only tried that once, just to see if there reallty was TWO bad
thermostats.
(I am on #3 now in the $300 hunt).
I really think this is just not pumping enough water and under a load it
overloads the ability to cool. Simple huh?
You can see why I really want to swap the whole damned foot.

Anyone want to take a shot an an overheating problem?
 

LD wrote:
You may have given us a clue, with the low psi. Where did you take the
reading? top of the block? before or after the thermostat? Also, what is
your water source? Are you using the clamp on "ears" or is the foot
submerged? I'm not sure of the spec for your particular motor (my 200hp 2
stroke climbs up to 10-15 psi at idle and 20-25 at 4-5000rpms) but some
motors are half that. No matter, 2-4 psi taken properly at 2000-4000rpm
sounds way too low. Assuming the impeller is correct and installed
correctly, something in the line is leaking and preventing pressure from
building.

On another note, Are the new plugs of the same heat range? A "hotter" plug
could be the culprit.
LD

"Greg" wrote in message
...

I have a 2002 4 stroke 60 HP Merc.
I took it in for the 500 hr and everything was fine before I took it in.

$437

later (a new impeller, plugs and an oil change) I have an overheating

problem

when I go over 4000 RPM.
I get Mercury involved and they say go to another dealer. $350 later (lots

of

easter egging around, a new thermostat, a housing THEY BROKE and another
impeller) and I am still overheating. I hooked up a guage and it is 4PSI

until

the thermostat opens then it is more like 2PSI. RPMs don't seem to change

it

much and whenever I get much over 3000 RPM I see the temp climbing. At

4000 it

is very hot and the beeper goes off.
I am collecting a white pasty substance around the thermostat that I think

is a

result of evaporating salt water since the flow is so low. Even when it is

all

flushed out I am still having the problem.




It's not the pressure, it's the flow.

I would be very picky in 2 areas:

1. Is there a foreign object somewhere, blocking normal flow near
the discharge of the water pump?

2. Is there a part missing in the impeller area, like a crescent
shaped filler that turns the impeller body into a pump, or a key,
set screw, or shim?

It sure seems like the trained monkeys at dealer 1 are having fun
laughing at the trained monkeys at dealer 2.

It was working before the 1-chimps got at it, right?

You should be talking lawsuit, if only you could find a real
mechanic to fix what the chimp did and write you an invoice stating
that they put the key back in your impeller shaft drive, or
retrieved and replaced the missing pump piece, whatever, perhaps
even installing a gasket upside down, or losing a set screw and not
bother finding it because "There were two, and one seemd enough"?

I had a similar problem with my oil pump. a ball bearing fell out
and into the crank mains. It ran good (!) but had no oil pressure to
speak of, so it got shut off real quick. The problem was compounded
by a defective replacement oil gague.

After a couple of go arounds, I shook the block, the ball fell out,
and once reassembled, all was well. Ask why I shook the block? I
deduced there must be a part missing from the oil pump, and it had
to be a ball bearing, and it had to be inside the crank main bearing
channel just from looking and thinking. I had to grok the oil pump,
having no manual. Who would have thought an oil pump needed two
loose ball bearings rattling around in the discharge outlet?

If you pump water through the block, it should not overheat.
Somebody diddled your pump.

Here's hoping yours is just another "Bloody chimpanzee mechanic"
story. There must be millions of them. The chimps tell the best
ones, which often involve 17 wheelers and miraculous survivals. They
never own up, even when the repo guys take their cars to pay legal
bills. It's always Somebod Yelse's fault.

Good luck.

Terry K

Anyone want to take a shot an an overheating problem?
 

This thing has been apart several times and the key is there.
I agree this is probably a foreign object but nobody has been able to find it.

Anyone want to take a shot an an overheating problem?
 

"Greg" wrote in message
...


It will not fail on a trailer. The boat needs to be pushing
water to be running hard enough to overheat.

When you measured the water pressure, was that sitting at idle, or while
running? Does the motor have a "pee hole", and if it does, can you see a
good stream of water coming out?

I am wondering if the problem isn't some factor involving the boat, like
maybe the motor is mounted too high and the pump is sucking air. That could
be a problem when the boat is up on plane, but shouldn't be a problem while
sitting idle.


I really think this is just not pumping enough water and under a load it
overloads the ability to cool. Simple huh?
You can see why I really want to swap the whole damned foot.


The first thing I would try is to remove the foot and disassemble the water
pump. Clamp on the "ear muffs" to connect the water hose and turn the water
on. The pressure from the hose should send a good stream of water into the
pump housing.

If that looks good, then the next thing I would try it to connect a hose to
the water tube that goes up into the motor. You should be able to come up
with some combination of hoses and fittings that will allow you to clamp a
hose to the water supply tube. If you want to get really fancy you could
throw a T on the faucet and connect a pressure gauge so you can see how much
pressure you are putting into the unit. Turn the hose on and see how much
water flows. If you have your engine water pressure gauge working you can
see how much hose pressure is required to get the desired engine manifold
pressure. That might tell you a lot.

You mentioned that they had to replace a broken housing. Was this a
thermostat housing? Do you have the old one? I am thinking that you might
be able to take the broken housing, modify it to add a hose barb and use it
to back flush the upper unit. If there is a blockage in the upper unit
someplace then creating a reverse flow might wash it out.

I suppose the worst thing is that you had some sort of critter get into
the cooling system when it was really small, and then grow to such a size
that it is creating a blockage and it can't wash out.

Rod

Anyone want to take a shot an an overheating problem?
 

My neighbor has a motor similar to mine and I am thinking about swapping the
foot with him to cut this problerm in half but that is a lot to ask.

Greg,
That would be a quick easy thing to try. But you are right, it's a lot to ask.
In a perfect world your dealer would have one to try. I would not be happy
bringing my boat in for repair, paying good money, only to find out it wasn't
fixed.
The possibility of a blown head gasket /cracked head is there, but I would
personally eliminate the lower unit/ water pump first.2PSI doesn't sound like
much water pressure at 4000 rpms. What is the spec on it?

BR

Anyone want to take a shot an an overheating problem?
 

I am wondering if the problem isn't some factor involving the boat, like
maybe the motor is mounted too high and the pump is sucking air. That could
be a problem when the boat is up on plane, but shouldn't be a problem while
sitting idle.

The pressure is always low. This is either sitting, slow speed or up on the
step. I am still using the boat. (138 hours since it started) There is no
problem if I stay under 4000 RPM. With 50 square miles of manatee zones that is
not a problem.

If that looks good, then the next thing I would try it to connect a hose to
the water tube that goes up into the motor.

I have tried pushing water up the pipe. It seemed to flow pretty good with the
thermostat cover off but I didn't want to build up much pressure and blow a
gasket so I was just going easy with the hose.

I also back flushed it from the thermostat hole down to the pipe. It seemed to
flow OK but I don't really have a reference to how good that is supposed to be.



I suppose the worst thing is that you had some sort of critter get into
the cooling system


My biggest fear is that "critter" is something the first dealer did.

The last words out of his mouth when I left it with him was "if this thing was
running a little hotter it wouldn't make oil" and some mumbled reference to
cutting off an impeller ear. I'm afraid they did something.

The next step is probably pulling the water manifold cover and looking for a
dead rat but that is going to be the dealer, not me.

Anyone want to take a shot an an overheating problem?
 

2PSI doesn't sound like
much water pressure at 4000 rpms. What is the spec on it?


The best I can tell it is 16 lbs.
I had it out tonight and I start out at about 4.5 psi until the thermostat
opens and then I am back to 2 or so. I really think the water supply tube or
the manifold must be plugged. with limited flow the pump pressure will max out
at a pretty low RPM (water starts blowing by the impeller), then more RPM won't
do much for the pressure.
I am really thinking if I get back in there myself I will make a snake from a
screen door spring and snake out that pipe.

Anyone want to take a shot an an overheating problem?
 

"Greg" wrote
Blown head gasket. Do a compression test.

How does that lower water pressure?

I didn't say it did.

You said:
I have an overheating problem when I go over 4000 RPM.

To which I replied:
Blown head gasket. Do a compression test.

Anyone want to take a shot an an overheating problem?
 

This will come across the wrong way, but I hope you don't get it fixed for
another week or so. This is a really interesting discussion so far. :-)

Anyone want to take a shot an an overheating problem?
 

This will come across the wrong way, but I hope you don't get it fixed for
another week or so. This is a really interesting discussion so far. :-)


It has been going on since October and the next time they will be taking a
swing at it is Tuesday so I think that is a safe bet.

Anyone want to take a shot an an overheating problem?
 

"Greg" wrote in message
...
This will come across the wrong way, but I hope you don't get it fixed
for
another week or so. This is a really interesting discussion so far. :-)


It has been going on since October and the next time they will be taking a
swing at it is Tuesday so I think that is a safe bet.


Well, keep posting. Murphy's Law says this is bound to happen to MY outboard
at some point. If the last few years are any indication, it'll happen during
the week of August 14th, when I'll be on vacation, trying to fish for 19
hours per day.

Anyone want to take a shot an an overheating problem?
 

"Greg" wrote in message
...
I have a 2002 4 stroke 60 HP Merc.


I happened to have the lower unit off of my 2000 50 Hp Mercury outboard last
night so I was able to refresh my memory on how everything in there looked.

The pump housing has a very short lip on the output that has to mate up with
a rubber hose/coupling to the upper unit. There is not much engagement in
these two pieces. I can see where a problem such as yours would occur if the
rubber coupling did not line up with the pump output. I can picture that
the lower unit would bolt up just fine with the pump output only partially
lined up with the rubber coupling. You would get some water flow but no
pressure.

I would drop the lower unit again and look closely at the rubber coupling.
If the metal lip of the pump housing was pushing against the bottom of the
coupling, instead of going inside it, you might be able to see a line where
the sharp metal pushed against the coupling.

If you are still not sure, try putting a glob of grease around the pump
output. Put it together, take it apart and inspect the grease. If the
coupling went on like it was supposed to it would have displaced all the
grease. If the grease is still there, then you know that things didn't mate
up like they were supposed to

Rod

Anyone want to take a shot an an overheating problem?
 

Yup we tried that, even put some silicone grease in the sleeve to verify how
far the pump housing engages the sleeve but I think it is that kind of
problem.
It has to be a leak or an obstruction in that tube.