I have a 1986 fresh water cooled Mercruiser 170HP 4 cylinder engine,
that I am trying to get repaired. I have some questions.

I am getting some tapping sounds from the front top end. How do I tell
if the oil is flowing throughout the engine? The oil gauge shows pressure.

My lower unit shows no sign of circulating water into the heat
exchanger. Does anyone know how to add a weep hole so i can visually see
the flow?

Thank you

Jim Rojas

On May 31, 9:28 pm, Jim Rojas wrote:
I have a 1986 fresh water cooled Mercruiser 170HP 4 cylinder engine,
that I am trying to get repaired. I have some questions.

I am getting some tapping sounds from the front top end. How do I tell
if the oil is flowing throughout the engine? The oil gauge shows pressure.

My lower unit shows no sign of circulating water into the heat
exchanger. Does anyone know how to add a weep hole so i can visually see
the flow?

Thank you

Jim Rojas


Heat exchanger? Jim I think you have an enclosed water system, But if
it IS truely a raw water system, you should be able to put it on a
water hose with "muffs" and when runnning, you should have water
splattering out the exhause (directly under the Gimbal bering housing)
and though the propeller.

comcerning the "tap" noise, It's possible that you have a rocker arm
needing adjusting, or replacing. interesting that witht he oil pump
located at the back of the engine, it has to pump oil through the back
to the front, and the rocker arm is at the very top, in the front, and
is the last item to be lubricated. Therefore it's not the case of
starving for lubrication, but rather, a point that the lubrication is
at it's least pressure. It's not uncommon especially an engine that
may have several hr's on it.

I was under the impression that the seawater helped to cool the
antifreeze, since there is no fan. That's why I said heat exchanger. I
will check to see if the thermostat is opening, and if i can see the
water pump flow.

Can I run the engine with the valve cover off? I don't want oil shooting
up at me while I check and see if the oil is pumping through to the
front end.

Thank you for the reply.

Jim Rojas



Tim wrote:
On May 31, 9:28 pm, Jim Rojas wrote:
I have a 1986 fresh water cooled Mercruiser 170HP 4 cylinder engine,
that I am trying to get repaired. I have some questions.

I am getting some tapping sounds from the front top end. How do I tell
if the oil is flowing throughout the engine? The oil gauge shows pressure.

My lower unit shows no sign of circulating water into the heat
exchanger. Does anyone know how to add a weep hole so i can visually see
the flow?

Thank you

Jim Rojas


Heat exchanger? Jim I think you have an enclosed water system, But if
it IS truely a raw water system, you should be able to put it on a
water hose with "muffs" and when runnning, you should have water
splattering out the exhause (directly under the Gimbal bering housing)
and though the propeller.

comcerning the "tap" noise, It's possible that you have a rocker arm
needing adjusting, or replacing. interesting that witht he oil pump
located at the back of the engine, it has to pump oil through the back
to the front, and the rocker arm is at the very top, in the front, and
is the last item to be lubricated. Therefore it's not the case of
starving for lubrication, but rather, a point that the lubrication is
at it's least pressure. It's not uncommon especially an engine that
may have several hr's on it.

On Jun 1, 11:08 am, Jim Rojas wrote:
I was under the impression that the seawater helped to cool the
antifreeze, since there is no fan. That's why I said heat exchanger. I
will check to see if the thermostat is opening, and if i can see the
water pump flow.

Can I run the engine with the valve cover off? I don't want oil shooting
up at me while I check and see if the oil is pumping through to the
front end.

Thank you for the reply.

Jim Rojas



Tim wrote:
On May 31, 9:28 pm, Jim Rojas wrote:
I have a 1986 fresh water cooled Mercruiser 170HP 4 cylinder engine,
that I am trying to get repaired. I have some questions.

I am getting some tapping sounds from the front top end. How do I tell
if the oil is flowing throughout the engine? The oil gauge shows pressure.

My lower unit shows no sign of circulating water into the heat
exchanger. Does anyone know how to add a weep hole so i can visually see
the flow?

Thank you

Jim Rojas

Heat exchanger? Jim I think you have an enclosed water system, But if
it IS truely a raw water system, you should be able to put it on a
water hose with "muffs" and when runnning, you should have water
splattering out the exhause (directly under the Gimbal bering housing)
and though the propeller.

comcerning the "tap" noise, It's possible that you have a rocker arm
needing adjusting, or replacing. interesting that witht he oil pump
located at the back of the engine, it has to pump oil through the back
to the front, and the rocker arm is at the very top, in the front, and
is the last item to be lubricated. Therefore it's not the case of
starving for lubrication, but rather, a point that the lubrication is
at it's least pressure. It's not uncommon especially an engine that
may have several hr's on it.- Hide quoted text -

- Show quoted text -

Many boat engines simply pump the lake/sea water through the engine in
place of antifreeze. A few do have a real heat exchanger that would
be the equivilent of a radiator. Usually you can tell pretty easily
as the heat exchanger is pretty big and has a number of hoses going to
it. You can't add a weep hole. There is a rubber impeller pump in
the lower unit that should be checked regularly. Merc recomends
yearly but most people do not as it is a pain to remove the bottom
half of the drive to check it. Every couple years is more common.
Unless you really use the boat a lot.

It will spray some oil when running with the valve cover off. I'd
save that as a last resort. If it did no thave oil pressure then it
would have locked up by now. The mains do not survive for more than
an few minutes without oil. You may be able to tell if you have a
loose rocker arm without it running by physically examining them.
They are hydralic so there should be zero lash. A manual will have
the correct adjustment procedure if they are adjustable. In any case
a manual would be a good idea if you plan on doing your own work.
There are clymers manuals for that year engine. The manuals are
engine specific, not boat specific, as a 4 cylinder merc is the same
no matter what the boat brand is.

jamesgangnc wrote:
On Jun 1, 11:08 am, Jim Rojas wrote:
I was under the impression that the seawater helped to cool the
antifreeze, since there is no fan. That's why I said heat exchanger. I
will check to see if the thermostat is opening, and if i can see the
water pump flow.

Can I run the engine with the valve cover off? I don't want oil shooting
up at me while I check and see if the oil is pumping through to the
front end.

Thank you for the reply.

Jim Rojas



Tim wrote:
On May 31, 9:28 pm, Jim Rojas wrote:
I have a 1986 fresh water cooled Mercruiser 170HP 4 cylinder engine,
that I am trying to get repaired. I have some questions.
I am getting some tapping sounds from the front top end. How do I tell
if the oil is flowing throughout the engine? The oil gauge shows pressure.
My lower unit shows no sign of circulating water into the heat
exchanger. Does anyone know how to add a weep hole so i can visually see
the flow?
Thank you
Jim Rojas
Heat exchanger? Jim I think you have an enclosed water system, But if
it IS truely a raw water system, you should be able to put it on a
water hose with "muffs" and when runnning, you should have water
splattering out the exhause (directly under the Gimbal bering housing)
and though the propeller.
comcerning the "tap" noise, It's possible that you have a rocker arm
needing adjusting, or replacing. interesting that witht he oil pump
located at the back of the engine, it has to pump oil through the back
to the front, and the rocker arm is at the very top, in the front, and
is the last item to be lubricated. Therefore it's not the case of
starving for lubrication, but rather, a point that the lubrication is
at it's least pressure. It's not uncommon especially an engine that
may have several hr's on it.- Hide quoted text -
- Show quoted text -

Many boat engines simply pump the lake/sea water through the engine in
place of antifreeze. A few do have a real heat exchanger that would
be the equivilent of a radiator.

The '86 era 165/170 Mercruiser is a closed cooling system(this is a
later version of the infamous 470).

Rob


Usually you can tell pretty easily
as the heat exchanger is pretty big and has a number of hoses going to
it. You can't add a weep hole. There is a rubber impeller pump in
the lower unit that should be checked regularly. Merc recomends
yearly but most people do not as it is a pain to remove the bottom
half of the drive to check it. Every couple years is more common.
Unless you really use the boat a lot.

It will spray some oil when running with the valve cover off. I'd
save that as a last resort. If it did no thave oil pressure then it
would have locked up by now. The mains do not survive for more than
an few minutes without oil. You may be able to tell if you have a
loose rocker arm without it running by physically examining them.
They are hydralic so there should be zero lash. A manual will have
the correct adjustment procedure if they are adjustable. In any case
a manual would be a good idea if you plan on doing your own work.
There are clymers manuals for that year engine. The manuals are
engine specific, not boat specific, as a 4 cylinder merc is the same
no matter what the boat brand is.

Do you know if there is any way to add a weep hole so I can tell that my
lower unit impeller is working? My previous boat had a 150HP Mariner
outboard. The weephole is a great feature to prevent blowing the motor.
And of course the alarm would go off. I sometimes go to a large lake
that is full of some kind of fresh water kelp growth.

Thanks

Jim Rojas



trainfan1 wrote:
jamesgangnc wrote:
On Jun 1, 11:08 am, Jim Rojas wrote:
I was under the impression that the seawater helped to cool the
antifreeze, since there is no fan. That's why I said heat exchanger. I
will check to see if the thermostat is opening, and if i can see the
water pump flow.

Can I run the engine with the valve cover off? I don't want oil shooting
up at me while I check and see if the oil is pumping through to the
front end.

Thank you for the reply.

Jim Rojas



Tim wrote:
On May 31, 9:28 pm, Jim Rojas wrote:
I have a 1986 fresh water cooled Mercruiser 170HP 4 cylinder engine,
that I am trying to get repaired. I have some questions.
I am getting some tapping sounds from the front top end. How do I tell
if the oil is flowing throughout the engine? The oil gauge shows
pressure.
My lower unit shows no sign of circulating water into the heat
exchanger. Does anyone know how to add a weep hole so i can
visually see
the flow?
Thank you
Jim Rojas
Heat exchanger? Jim I think you have an enclosed water system, But if
it IS truely a raw water system, you should be able to put it on a
water hose with "muffs" and when runnning, you should have water
splattering out the exhause (directly under the Gimbal bering housing)
and though the propeller.
comcerning the "tap" noise, It's possible that you have a rocker arm
needing adjusting, or replacing. interesting that witht he oil pump
located at the back of the engine, it has to pump oil through the back
to the front, and the rocker arm is at the very top, in the front, and
is the last item to be lubricated. Therefore it's not the case of
starving for lubrication, but rather, a point that the lubrication is
at it's least pressure. It's not uncommon especially an engine that
may have several hr's on it.- Hide quoted text -
- Show quoted text -

Many boat engines simply pump the lake/sea water through the engine in
place of antifreeze. A few do have a real heat exchanger that would
be the equivilent of a radiator.

The '86 era 165/170 Mercruiser is a closed cooling system(this is a
later version of the infamous 470).

Rob


Usually you can tell pretty easily
as the heat exchanger is pretty big and has a number of hoses going to
it. You can't add a weep hole. There is a rubber impeller pump in
the lower unit that should be checked regularly. Merc recomends
yearly but most people do not as it is a pain to remove the bottom
half of the drive to check it. Every couple years is more common.
Unless you really use the boat a lot.

It will spray some oil when running with the valve cover off. I'd
save that as a last resort. If it did no thave oil pressure then it
would have locked up by now. The mains do not survive for more than
an few minutes without oil. You may be able to tell if you have a
loose rocker arm without it running by physically examining them.
They are hydralic so there should be zero lash. A manual will have
the correct adjustment procedure if they are adjustable. In any case
a manual would be a good idea if you plan on doing your own work.
There are clymers manuals for that year engine. The manuals are
engine specific, not boat specific, as a 4 cylinder merc is the same
no matter what the boat brand is.

Jim Rojas wrote:
Do you know if there is any way to add a weep hole so I can tell that my
lower unit impeller is working? My previous boat had a 150HP Mariner
outboard. The weephole is a great feature to prevent blowing the motor.
And of course the alarm would go off. I sometimes go to a large lake
that is full of some kind of fresh water kelp growth.

Thanks

Jim Rojas



There already is one, of sorts.

The exhaust manifold is raw water cooled, and exits the drive through
the exhaust relief ports in the gimbal housing. BUT, you can't see this
while under way, and it takes a trained ear to notice the difference at
speed if your impeller fails you. You should familiarize yourself with
the temperature gauge and how it indicates while everything is working.
This will be your best indicator. There may also be a temp warning
horn, I can't recall.

If you feel you cannot proceed w/o a telltale, you may be able to splice
into the line the feeds the exhaust manifold and attach a small diameter
tube to pee within sight of the helm. Where that would be on an I/O I
haven't a clue. I don't know if there is enough pressure at that point
either, or if it will sap enough volume off of the manifold to cause an
overheating issue.

Rob



The '86 era 165/170 Mercruiser is a closed cooling system(this is a
later version of the infamous 470).

Rob

Several million merc owners have managed to get aling without one. Move on.

"Jim Rojas" wrote in message
...
Do you know if there is any way to add a weep hole so I can tell that my
lower unit impeller is working? My previous boat had a 150HP Mariner
outboard. The weephole is a great feature to prevent blowing the motor.
And of course the alarm would go off. I sometimes go to a large lake that
is full of some kind of fresh water kelp growth.

Thanks

Jim Rojas



trainfan1 wrote:
jamesgangnc wrote:
On Jun 1, 11:08 am, Jim Rojas wrote:
I was under the impression that the seawater helped to cool the
antifreeze, since there is no fan. That's why I said heat exchanger. I
will check to see if the thermostat is opening, and if i can see the
water pump flow.

Can I run the engine with the valve cover off? I don't want oil
shooting
up at me while I check and see if the oil is pumping through to the
front end.

Thank you for the reply.

Jim Rojas



Tim wrote:
On May 31, 9:28 pm, Jim Rojas wrote:
I have a 1986 fresh water cooled Mercruiser 170HP 4 cylinder engine,
that I am trying to get repaired. I have some questions.
I am getting some tapping sounds from the front top end. How do I
tell
if the oil is flowing throughout the engine? The oil gauge shows
pressure.
My lower unit shows no sign of circulating water into the heat
exchanger. Does anyone know how to add a weep hole so i can visually
see
the flow?
Thank you
Jim Rojas
Heat exchanger? Jim I think you have an enclosed water system, But if
it IS truely a raw water system, you should be able to put it on a
water hose with "muffs" and when runnning, you should have water
splattering out the exhause (directly under the Gimbal bering housing)
and though the propeller.
comcerning the "tap" noise, It's possible that you have a rocker arm
needing adjusting, or replacing. interesting that witht he oil pump
located at the back of the engine, it has to pump oil through the back
to the front, and the rocker arm is at the very top, in the front, and
is the last item to be lubricated. Therefore it's not the case of
starving for lubrication, but rather, a point that the lubrication is
at it's least pressure. It's not uncommon especially an engine that
may have several hr's on it.- Hide quoted text -
- Show quoted text -

Many boat engines simply pump the lake/sea water through the engine in
place of antifreeze. A few do have a real heat exchanger that would
be the equivilent of a radiator.

The '86 era 165/170 Mercruiser is a closed cooling system(this is a later
version of the infamous 470).

Rob


Usually you can tell pretty easily
as the heat exchanger is pretty big and has a number of hoses going to
it. You can't add a weep hole. There is a rubber impeller pump in
the lower unit that should be checked regularly. Merc recomends
yearly but most people do not as it is a pain to remove the bottom
half of the drive to check it. Every couple years is more common.
Unless you really use the boat a lot.

It will spray some oil when running with the valve cover off. I'd
save that as a last resort. If it did no thave oil pressure then it
would have locked up by now. The mains do not survive for more than
an few minutes without oil. You may be able to tell if you have a
loose rocker arm without it running by physically examining them.
They are hydralic so there should be zero lash. A manual will have
the correct adjustment procedure if they are adjustable. In any case
a manual would be a good idea if you plan on doing your own work.
There are clymers manuals for that year engine. The manuals are
engine specific, not boat specific, as a 4 cylinder merc is the same
no matter what the boat brand is.

Pop the feed hose from the stern drive to the heat exchanger. See if water
comes out when you run the engine for 30 seconds. Alternately, you can
loosen one of the heat exchanger end caps. Those engines clatter a lot but
quiet down some when warm.
Jim
"Jim Rojas" wrote in message
...
I have a 1986 fresh water cooled Mercruiser 170HP 4 cylinder engine, that I
am trying to get repaired. I have some questions.

I am getting some tapping sounds from the front top end. How do I tell if
the oil is flowing throughout the engine? The oil gauge shows pressure.

My lower unit shows no sign of circulating water into the heat exchanger.
Does anyone know how to add a weep hole so i can visually see the flow?

Thank you

Jim Rojas

On Mon, 25 Jun 2007 19:30:43 -0600 (MDT), Dan
wrote:


Their lo-carb breakfast bowl is to Eric Clapton?

Running through "Thou fool! No water came out.

Know a guy that has everything you would be an example of the
high end foodie butchers here, and besides (with current
technology) being a liberal education system. Around 3 weeks
prior to the side. Of course, the original diesel engine but no
bites. Experienced boat buyers is not befitting you.

`becalm ink a ne the clooked iraid dontord, wittimpaithe irome deced
thervere thisterecame and to ve

mnet of thadell ithe or my of to had roness overy cut wast inion anten
Mrs a pled shinnill sto barms

Keeng. `Have, hyarsed ras the hearfuld at's but, als. The Rog
saidencepeablefords ate, on what sup m

Whe did of and a bruce!' hithed. `Ah!'' sawartated if his of ase up,
`Not more's that I cournestir

y-moser, of wassit taid frobst making! Dutted numb-but opsly; `Then
tome sole hailter unionitake old