I am trying to run a 1995 Mercury 115HP 2-stroke outboard motor for 10
minutes in order to get the treated fuel to the fuel system (for
winterizing). Because I am doing this out of the water, I need to use
a flush-earmuffs to pump water to the lower unit. But I am having some
problems in using the flush-earmuffs:

- I was setting the water pressure to about half way. But I didn't
see the "telltale" sign of water stream coming out from the back of the
motor when I was running the motor. All I saw was water coming out
from around the flush-earmuff, and from around the propeller. Is that
normal? Should I increase the water pressure (knowing that I should
not use full water pressure)?

- I saw that the engine temperature steadily went up from 100-degree
to 170-degree (during the period of 4 minutes). At that point, I was
afraid that I might overheat the motor; therefore, I turned off the
motor. Did the motor not getting enough water cooling?

- During the sea-trial of the boat just a couple weeks ago, I saw the
telltale sign of water coming out from the back of the motor.
Therefore, I know that the water pump worked. I am wondering why the
flush earmuffs doesn't seem to delivery the desired result?

- I guess one of the alternative is to put the motor into a water tank
instead of using a flush earmuff. Where can I find a water tank big
enough for a 115HP outboard motor? I measure that the water tank needs
to be at least 21" tall and 24" wide. I have a feeling that a plastic
container probably will not hold up the water pressure, right? Where
do people get their water tanks for this purpose?

Thanks in advance for any info.

Jay Chan

wrote:
: I am trying to run a 1995 Mercury 115HP 2-stroke outboard motor for 10
: minutes in order to get the treated fuel to the fuel system (for
: winterizing). Because I am doing this out of the water, I need to use
: a flush-earmuffs to pump water to the lower unit. But I am having some
: problems in using the flush-earmuffs:

: - I was setting the water pressure to about half way. But I didn't
: see the "telltale" sign of water stream coming out from the back of the
: motor when I was running the motor. All I saw was water coming out
: from around the flush-earmuff, and from around the propeller. Is that
: normal? Should I increase the water pressure (knowing that I should
: not use full water pressure)?

Turn the water faucett on completely open, not 1/2 way. I don't know why
anyone would want to run the risk of overheating an engine by turning
it on 1/2 way.

Note that you will be putting pressurized water in to the impeller with
the hose adapter. That may mask a problem with the impeller. Using
a barrell isn't a good idea with a 115 HP engine. It will heat up
quickly.

Keep an eye on the temperature gauge as you have been doing.

b.

wrote:
I am trying to run a 1995 Mercury 115HP 2-stroke outboard motor for 10
minutes in order to get the treated fuel to the fuel system (for
winterizing). Because I am doing this out of the water, I need to use
a flush-earmuffs to pump water to the lower unit. But I am having some
problems in using the flush-earmuffs:

- I was setting the water pressure to about half way. But I didn't
see the "telltale" sign of water stream coming out from the back of the
motor when I was running the motor. All I saw was water coming out
from around the flush-earmuff, and from around the propeller. Is that
normal? Should I increase the water pressure (knowing that I should
not use full water pressure)?

- I saw that the engine temperature steadily went up from 100-degree
to 170-degree (during the period of 4 minutes). At that point, I was
afraid that I might overheat the motor; therefore, I turned off the
motor. Did the motor not getting enough water cooling?

- During the sea-trial of the boat just a couple weeks ago, I saw the
telltale sign of water coming out from the back of the motor.
Therefore, I know that the water pump worked. I am wondering why the
flush earmuffs doesn't seem to delivery the desired result?

- I guess one of the alternative is to put the motor into a water tank
instead of using a flush earmuff. Where can I find a water tank big
enough for a 115HP outboard motor? I measure that the water tank needs
to be at least 21" tall and 24" wide. I have a feeling that a plastic
container probably will not hold up the water pressure, right? Where
do people get their water tanks for this purpose?

Thanks in advance for any info.

Jay Chan

I've never had any trouble running an outboard on the muffs. I'd try
adjusting the pressure, if I knew that the water temperature was
getting warm enough to open the thermostat.

I'm wodering if you have a bad water pump in the lower end?

wrote:
I'm wodering if you have a bad water pump in the lower end?

No, the telltale had a stream flowing during sea trial.

I've never had any trouble running an outboard on the muffs. I'd try
adjusting the pressure, if I knew that the water temperature was
getting warm enough to open the thermostat.

I have solved the problem by running the motor in a small water tank.
With this setup, I can see the telltate water stream coming out that I
could not see when I used the flushing earmuffs. And the motor
temperature didn't go over 130 degree when I ran the motor for 10
minutes.

I still cannot figure out why the flushing earmuffs cannot give me the
desired result. May be I should have increased the water pressure to
almost full pressure. But I don't want to risk damaging the impeller
in the water pump. Moreover the small water tank is _much_ cheaper
than the flushing earmuffs ($5 vs $30). Seem like I am better off
using the small water tank instead of worrying about how to get the
flushing earmuffs working.

Jay Chan

wrote:
I've never had any trouble running an outboard on the muffs. I'd try
adjusting the pressure, if I knew that the water temperature was
getting warm enough to open the thermostat.


I have solved the problem by running the motor in a small water tank.
With this setup, I can see the telltate water stream coming out that I
could not see when I used the flushing earmuffs. And the motor
temperature didn't go over 130 degree when I ran the motor for 10
minutes.

I still cannot figure out why the flushing earmuffs cannot give me the
desired result. May be I should have increased the water pressure to
almost full pressure. But I don't want to risk damaging the impeller
in the water pump. Moreover the small water tank is _much_ cheaper
than the flushing earmuffs ($5 vs $30). Seem like I am better off
using the small water tank instead of worrying about how to get the
flushing earmuffs working.

Jay Chan


Don't forget, that water in the 'small tank' will heat up because of the
exhaust .

Don't forget, that water in the 'small tank' will heat up because of the
exhaust.

The lower-unit threw so much water out from the propeller area that I
needed to constantly adding water into the small water tank. I believe
this takes care of the water-becoming-warm problem.

Thanks for the warning though. I will check the water temperature in
the water tank next time when I need to flush the motor again.

Jay Chan