"Greg O" wrote in message ...
"Eldon Cutlip" wrote in message
om...

So, I was thinking I must need have a semi-bad impeller in both motors
at this point. So, I just took apart the lower unit and pulled the
water pump on the cold motor. The impeller looked fine - no wear or
tear and still quite bendy. The inside of the water pump lining
doesn't have any scratches. So now I'm totally out of ideas.

Replace the impellers. even if they look good they may not be. A few years
ago my dad was up in Canada fishing and the engine was running hot. Removed
the leg and "flipped" the impeller over. The engine ran fine the rest of the
trip. The impeller got changed ASAP!
Greg

I replaced the water pump in the "cold" motor - or at least the one
that was cold originally After that, I had just enough time to
idle it for 5 or 10 minutes on the ears. It settled right at the mark
between the green and red. I didn't have a chance to get the other
engine's water pump done yet or to take the cold one out on the water.
But something still seems wrong even with the cold motor. I think I
will have to buy one of those laser temperature things. And I think
someone had mentioned that the oil to fuel mixture may be suspect.
Could running too lean cause the engines to run hotter? If so how do
I verify what the oil mixture is set to (these are the VRO Johnson
70's - 1986)? I had two of the local boat mechanics tell me the new
thermostats are the same as the ones I replaced.

So, I think the plan right now is replace the other water pump, get a
laser, and verify the oil mixture. I have no clue how to verify the
oil mixture but I guess I could just put oil in the fuel tank and see
if they stay cooler.

Thanks,
Eldon

On 18 May 2004 08:40:40 -0700, (Eldon Cutlip)
wrote:

"Greg O" wrote in message ...
"Eldon Cutlip" wrote in message
om...

So, I was thinking I must need have a semi-bad impeller in both motors
at this point. So, I just took apart the lower unit and pulled the
water pump on the cold motor. The impeller looked fine - no wear or
tear and still quite bendy. The inside of the water pump lining
doesn't have any scratches. So now I'm totally out of ideas.

Replace the impellers. even if they look good they may not be. A few years
ago my dad was up in Canada fishing and the engine was running hot. Removed
the leg and "flipped" the impeller over. The engine ran fine the rest of the
trip. The impeller got changed ASAP!
Greg

I replaced the water pump in the "cold" motor - or at least the one
that was cold originally After that, I had just enough time to
idle it for 5 or 10 minutes on the ears. It settled right at the mark
between the green and red. I didn't have a chance to get the other
engine's water pump done yet or to take the cold one out on the water.
But something still seems wrong even with the cold motor. I think I
will have to buy one of those laser temperature things. And I think
someone had mentioned that the oil to fuel mixture may be suspect.
Could running too lean cause the engines to run hotter? If so how do
I verify what the oil mixture is set to (these are the VRO Johnson
70's - 1986)? I had two of the local boat mechanics tell me the new
thermostats are the same as the ones I replaced.

So, I think the plan right now is replace the other water pump, get a
laser, and verify the oil mixture. I have no clue how to verify the
oil mixture but I guess I could just put oil in the fuel tank and see
if they stay cooler.

Thanks,
Eldon

Without verifying that both your gauges are accurate and reliable..
....... you could be farting against thunder!

Derek wrote in message . ..
On 18 May 2004 08:40:40 -0700, (Eldon Cutlip)
wrote:

"Greg O" wrote in message ...
"Eldon Cutlip" wrote in message
om...

So, I was thinking I must need have a semi-bad impeller in both motors
at this point. So, I just took apart the lower unit and pulled the
water pump on the cold motor. The impeller looked fine - no wear or
tear and still quite bendy. The inside of the water pump lining
doesn't have any scratches. So now I'm totally out of ideas.

Replace the impellers. even if they look good they may not be. A few years
ago my dad was up in Canada fishing and the engine was running hot. Removed
the leg and "flipped" the impeller over. The engine ran fine the rest of the
trip. The impeller got changed ASAP!
Greg

I replaced the water pump in the "cold" motor - or at least the one
that was cold originally After that, I had just enough time to
idle it for 5 or 10 minutes on the ears. It settled right at the mark
between the green and red. I didn't have a chance to get the other
engine's water pump done yet or to take the cold one out on the water.
But something still seems wrong even with the cold motor. I think I
will have to buy one of those laser temperature things. And I think
someone had mentioned that the oil to fuel mixture may be suspect.
Could running too lean cause the engines to run hotter? If so how do
I verify what the oil mixture is set to (these are the VRO Johnson
70's - 1986)? I had two of the local boat mechanics tell me the new
thermostats are the same as the ones I replaced.

So, I think the plan right now is replace the other water pump, get a
laser, and verify the oil mixture. I have no clue how to verify the
oil mixture but I guess I could just put oil in the fuel tank and see
if they stay cooler.

Thanks,
Eldon

Without verifying that both your gauges are accurate and reliable..
...... you could be farting against thunder!

Well, my thinking was that the laser temperature gun would tell me
exactly what temperature my engines are running at. I thought I could
then see what the guage was reading and "mentally calibrate" for my
guages. How else can I verify my guages are accurate and reliable?

Eldon

On 19 May 2004 08:40:19 -0700, (Eldon Cutlip)
wrote:

Derek wrote in message . ..
On 18 May 2004 08:40:40 -0700, (Eldon Cutlip)
wrote:

"Greg O" wrote in message ...
"Eldon Cutlip" wrote in message
om...

So, I was thinking I must need have a semi-bad impeller in both motors
at this point. So, I just took apart the lower unit and pulled the
water pump on the cold motor. The impeller looked fine - no wear or
tear and still quite bendy. The inside of the water pump lining
doesn't have any scratches. So now I'm totally out of ideas.

Replace the impellers. even if they look good they may not be. A few years
ago my dad was up in Canada fishing and the engine was running hot. Removed
the leg and "flipped" the impeller over. The engine ran fine the rest of the
trip. The impeller got changed ASAP!
Greg

I replaced the water pump in the "cold" motor - or at least the one
that was cold originally After that, I had just enough time to
idle it for 5 or 10 minutes on the ears. It settled right at the mark
between the green and red. I didn't have a chance to get the other
engine's water pump done yet or to take the cold one out on the water.
But something still seems wrong even with the cold motor. I think I
will have to buy one of those laser temperature things. And I think
someone had mentioned that the oil to fuel mixture may be suspect.
Could running too lean cause the engines to run hotter? If so how do
I verify what the oil mixture is set to (these are the VRO Johnson
70's - 1986)? I had two of the local boat mechanics tell me the new
thermostats are the same as the ones I replaced.

So, I think the plan right now is replace the other water pump, get a
laser, and verify the oil mixture. I have no clue how to verify the
oil mixture but I guess I could just put oil in the fuel tank and see
if they stay cooler.

Thanks,
Eldon

Without verifying that both your gauges are accurate and reliable..
...... you could be farting against thunder!

Well, my thinking was that the laser temperature gun would tell me
exactly what temperature my engines are running at. I thought I could
then see what the guage was reading and "mentally calibrate" for my
guages. How else can I verify my guages are accurate and reliable?

Eldon


Wal-Mart sells mechanical temp gauges (made by Equius) for around $10.
They come with a good selection of fittings and mine is very accurate.
You should be able to install a "T" piece fitting that will accept
both your electric gauge and the mechanical one simultaniously. Try
vairying the the engine conditions (NEVER rev a motor above 2000
r.p.m. in neutral). The two gauges should follow each other closely.
Now, test the other motor. All done for around $15.

Just be careful not to kink the temp gauge line, it's filled with
liquid (alcohol, I think). Ideally, this test should be performed
under normal operating conditions.

Another method, but do this at your own risk, is to ground out the
wire to the sender unit via a selection of various resistors. For
example, if a 500 Ohm resistor takes the gauge to half, and a 200 Ohm
takes it to one quarter, it MUST do the same on the other gauge. Next,
remove the sender units and put them in a pot of warm water for a bit.
Using a digital multimeter, record the Ohms readings of both. Heat the
water a little more and repeat, all the way up to near boiling. I'm
guessing the readings should be within about 5% of each other.
Remember to make the readings quickly, for accuracy. Problem is, if
they're way out, which one is faulty???? This is why I preffer a
mechanical gauge over an electric gauge whenever possible, even for
Volts (joke!). Unfortunately, the pivoting and steering system of a
boat does not lend itself to these gauges, unless they're mounted on
the motor directly (another temporary option).

Okay, since I have a few minutes, and it were my boat, here's what I'd
do (at your own risk of course)

1) Replace the other impellor (water pump).
2) Ensure that all the seals between the pump and the head are good.
You could even be losing water pressure/volume from a leaking
seal or joint somewhere along that pipe (been there, done that).
3) Remove both thermostats, and leave housings open. BRIEFLY run
engines at idle and a little above. Both "fountains" should be
similar in volume and pressure (use drums, not ear muffs, for a
true simulation.)
4) Verify that both thermostats are working similarly, by using the
pot on a stove method.
5) Verify that both temperature gauges are accurate/reliable.
(also check for and clean any corrosion on any terminals).

Basically, you start at the beginning (pump) and logically eliminate
any discrepencies between the 2 motors.

I would also suggest getting a manual for your motor. They are
invaluable.

Good Luck.

Wal-Mart sells mechanical temp gauges (made by Equius) for around $10.
They come with a good selection of fittings and mine is very accurate.
You should be able to install a "T" piece fitting that will accept
both your electric gauge and the mechanical one simultaniously. Try
vairying the the engine conditions (NEVER rev a motor above 2000
r.p.m. in neutral). The two gauges should follow each other closely.
Now, test the other motor. All done for around $15.

Just be careful not to kink the temp gauge line, it's filled with
liquid (alcohol, I think). Ideally, this test should be performed
under normal operating conditions.

Another method, but do this at your own risk, is to ground out the
wire to the sender unit via a selection of various resistors. For
example, if a 500 Ohm resistor takes the gauge to half, and a 200 Ohm
takes it to one quarter, it MUST do the same on the other gauge. Next,
remove the sender units and put them in a pot of warm water for a bit.
Using a digital multimeter, record the Ohms readings of both. Heat the
water a little more and repeat, all the way up to near boiling. I'm
guessing the readings should be within about 5% of each other.
Remember to make the readings quickly, for accuracy. Problem is, if
they're way out, which one is faulty???? This is why I preffer a
mechanical gauge over an electric gauge whenever possible, even for
Volts (joke!). Unfortunately, the pivoting and steering system of a
boat does not lend itself to these gauges, unless they're mounted on
the motor directly (another temporary option).

Okay, since I have a few minutes, and it were my boat, here's what I'd
do (at your own risk of course)

1) Replace the other impellor (water pump).
2) Ensure that all the seals between the pump and the head are good.
You could even be losing water pressure/volume from a leaking
seal or joint somewhere along that pipe (been there, done that).
3) Remove both thermostats, and leave housings open. BRIEFLY run
engines at idle and a little above. Both "fountains" should be
similar in volume and pressure (use drums, not ear muffs, for a
true simulation.)
4) Verify that both thermostats are working similarly, by using the
pot on a stove method.
5) Verify that both temperature gauges are accurate/reliable.
(also check for and clean any corrosion on any terminals).

Basically, you start at the beginning (pump) and logically eliminate
any discrepencies between the 2 motors.

I would also suggest getting a manual for your motor. They are
invaluable.

Good Luck.

I really appreciate your time on this! I just got the manual via UPS
and my wife ordered one of the temperature laser gun things. And I
will be starting through your suggestions starting with the water pump
in the "hot" engine when I get back home this weekend.

Thanks!
Eldon

"Eldon Cutlip" wrote in message
om...


I really appreciate your time on this! I just got the manual via UPS
and my wife ordered one of the temperature laser gun things. And I
will be starting through your suggestions starting with the water pump
in the "hot" engine when I get back home this weekend.

Thanks!
Eldon


Be sure you install the factory water pump kit #432995 which contains
everything you need to replace it plus items to upgrade your cooling system.
You will get a different thermostat spring and a plastic water tell-tale
fitting that get relocated to the top of the exhaust housing to purge
trapped air in the system.

Remember that your temperature gauges are not precision instruments and that
the sender is only reading "skin temperature" of the motor, which may be
higher or lower than the internal water temp of the engine.

Keep us posted

Bill Grannis
service manager

I replaced the water pump in the "hot" engine. So, that meant I had
replaced the water pump in both engines and thermostats in both
engines. Someone else had already moved the pee hole connector to the
top of the exhaust housing on both engines. And someone else must
have already upgraded the springs on the thermostats. Because the kit
said I should just replace the straight spring that was in there with
the same straight string in the water pump kit. So I think I should
be good on all the water pump conversion things.

I then ran both engines (at idle on the ears) and they both got into
the red on my guages. The laser gun showed up to about 135 degrees at
the front of the thermostat housing and up to about 170 degrees
(varying though) at lower parts of the power head. So I decided I
better take it to the local professional before I screwed things up.
The mechanic called and said both engines were running great. He said
they were both below 150 degrees and that they ran them up to 2000
rpms. He said he believed the sending units on the guages were bad
because they looked pretty corroded. He said he was going to see when
he could get some in and maybe look at getting me set up with water
pressure guages instead (he thought they would be a better indicator
of a good cooling system - and I still have the overheat warning
horn). But then he called back later and said they do not make the
sending units or guages for my motors anymore. He cleaned up my
sending units and replaced them. I took the boat out for the next
three days and the motors appeared to work great. No overheat alarm.
When one of the guages got up into the red the corresponding motor
appeared to be smoking more than when the guage showed in the green.
I was wondering if that could have something to do with the fact that
I mixed the gas in the tank 100 to 1 as a safeguard because I was
afraid the guages going in the red might be because the mix was too
lean. Does that seem possible at all? Also, do any of you guys know
what the part numbers for the sending units and guages would be and
where I might be able to find obsolete parts like those? My motors
are 1986 Johnson 70hp - model: J70TLCD I bought a parts manual but it
doesn't seem to include part numbers for the sending unit and
temperature guages.

Thanks very much for the help!
Eldon

"Derek" wrote



Wal-Mart sells mechanical temp gauges (made by Equius) for around $10.
They come with a good selection of fittings and mine is very accurate.

Which department at Walmart did you find it in?

Cam

On Thu, 20 May 2004 08:37:22 -0800, "Camilo"
wrote:


"Derek" wrote



Wal-Mart sells mechanical temp gauges (made by Equius) for around $10.
They come with a good selection of fittings and mine is very accurate.

Which department at Walmart did you find it in?

Cam


The Auto section, where they keep all the oil, Volt, Amp etc. gauges
for cars. They're pretty common at auto accesorie stores. I've seen
them at Canadian Tire here in Canada too.