Water pump - Johnson outboard
 

This is my first season prepping a boat for the water and
I have a question about maintenance of the water pump.
I've heard that you should change the impeller every 1 to 2 years.
I'm nervous about dropping the lower gear case to get at the pump.
I bought the boat last year, it was already in the water and ran
fine all season. I'm tempted to use the old "if it ain't broke" philosophy
but I'm sure this will get me into trouble at some point.

So two questions:
How often should an outboard water pump be serviced?
How hard is it to service the pump? Again I'm mostly concerned about
dropping the lower gear casing.
(BTW, it's a 1995 130HP Johnson)

Thanks in advance
-VI

"Vinny" wrote in message
...
This is my first season prepping a boat for the water and
I have a question about maintenance of the water pump.
I've heard that you should change the impeller every 1 to 2 years.
I'm nervous about dropping the lower gear case to get at the pump.
I bought the boat last year, it was already in the water and ran
fine all season. I'm tempted to use the old "if it ain't broke" philosophy
but I'm sure this will get me into trouble at some point.

So two questions:
How often should an outboard water pump be serviced?
How hard is it to service the pump? Again I'm mostly concerned about
dropping the lower gear casing.
(BTW, it's a 1995 130HP Johnson)

Thanks in advance
-VI



Since you do not know the condition of the pump/impeller currently in there,
I would replace it prior to use. I am a stickler for maintenance, and after
having Johnson, Evenrude, Mercury, Mariner, and Yamaha outboards, I would
not bother with the water pump more than every 3 years unless you use the
hell out of it, or operate in sandy, muddy water, which tends to where on
the impeller.

Not familiar with that particular HP, but in general, put in reverse, remove
the 4 or 6 bolts holding the lower on, plus the one above the fin anode.
Once that is loose, the shift shaft needs to be uncoupled, then drop the
lower, it is heavy.

Replace the entire pump 1st time, check seals below it for any possible
damage. When putting on your new impeller, a slight film of oil or Vaseline
will help work the impeller into the pump housing. MAKE SURE YOU PUT IT IN
THE RIGHT DIRECTION, look at the way the old one comes out.

Then assemble.

Get a service manual! Not to hard to change.

"Vinny" wrote in message
...
This is my first season prepping a boat for the water and
I have a question about maintenance of the water pump.
I've heard that you should change the impeller every 1 to 2 years.
I'm nervous about dropping the lower gear case to get at the pump.
I bought the boat last year, it was already in the water and ran
fine all season. I'm tempted to use the old "if it ain't broke" philosophy
but I'm sure this will get me into trouble at some point.

So two questions:
How often should an outboard water pump be serviced?
How hard is it to service the pump? Again I'm mostly concerned about
dropping the lower gear casing.
(BTW, it's a 1995 130HP Johnson)

Thanks in advance
-VI

On Wed, 20 Apr 2005 21:47:58 -0400, "Vinny"
wrote:

This is my first season prepping a boat for the water and
I have a question about maintenance of the water pump.
I've heard that you should change the impeller every 1 to 2 years.
I'm nervous about dropping the lower gear case to get at the pump.
I bought the boat last year, it was already in the water and ran
fine all season. I'm tempted to use the old "if it ain't broke" philosophy
but I'm sure this will get me into trouble at some point.

So two questions:
How often should an outboard water pump be serviced?

One to two years is over kill. Maybe five years at a minimum. Unless
there is a reason like running up a sandbar or operating in extremely
silty water.

How hard is it to service the pump? Again I'm mostly concerned about
dropping the lower gear casing.

Piece of cake. Get a service manual (like Seloc) for the engine.

(BTW, it's a 1995 130HP Johnson)

Nothing to it.

Later,

Tom

"Vinny" wrote in message
...
This is my first season prepping a boat for the water and
I have a question about maintenance of the water pump.
I've heard that you should change the impeller every 1 to 2 years.
I'm nervous about dropping the lower gear case to get at the pump.
I bought the boat last year, it was already in the water and ran
fine all season. I'm tempted to use the old "if it ain't broke" philosophy
but I'm sure this will get me into trouble at some point.

So two questions:
How often should an outboard water pump be serviced?
How hard is it to service the pump? Again I'm mostly concerned about
dropping the lower gear casing.
(BTW, it's a 1995 130HP Johnson)

Thanks in advance
-VI

Three reasons to replace the impeller with normal use. 1) Dirty water or
idling in shallow water can cause the impeller to wear out prematurely
(sand). 2) The impeller becomes less flexible and can loose it's shape
causing less water flow and poor priming (apx two-three years) . 3)
catastrophic failure because the rubber rotted (Aprox 5+years).

Another good reason to do it often is that the bolts will be easier to
remove.

Outdrives are easier to pop off and replace the impeller (45 min for me).

In article ,
says...
This is my first season prepping a boat for the water and
I have a question about maintenance of the water pump.
I've heard that you should change the impeller every 1 to 2 years.
I'm nervous about dropping the lower gear case to get at the pump.
I bought the boat last year, it was already in the water and ran
fine all season. I'm tempted to use the old "if it ain't broke" philosophy
but I'm sure this will get me into trouble at some point.

So two questions:
How often should an outboard water pump be serviced?
How hard is it to service the pump? Again I'm mostly concerned about
dropping the lower gear casing.
(BTW, it's a 1995 130HP Johnson)

Thanks in advance
-VI




I'm just finishing up the job on an 85 OMC and while the task isn't
overly taxing in the mechanical ability department it is a royal pain in
the ass.

The three most aggravating steps in the process, at least for me, is
disconnecting the shifting rod. The screw holding it in the upper unit
is buried in such a position it is bitch to get too. If yours in the
same position you'll need a socket wrench, an extension, and a universal
type connector between the end of the extension and the socket. Then
there fitting the impellers into the cup, and finally getting the pump
back on with the housing gasket/O ring still in place. Apply gasket
compound then let it set up and get good and tacky before trying to get
the darn thing in place.

As to how often to do the job - the impeller is rubber and it does take
a set. It fits very tightly into the stainless cup and any kind of
abrasive material that may get sucked in can have an adverse effect on
the rubber. Anyhow, sooner or later you are going to have to do the job.

Good luck.

--
Mike G.
Heirloom Woods

www.heirloom-woods.net

Jeff Rigby wrote:

-VI


Three reasons to replace the impeller with normal use. 1) Dirty water or
idling in shallow water can cause the impeller to wear out prematurely
(sand). 2) The impeller becomes less flexible and can loose it's shape
causing less water flow and poor priming (apx two-three years) . 3)
catastrophic failure because the rubber rotted (Aprox 5+years).

Another good reason to do it often is that the bolts will be easier to
remove.

Outdrives are easier to pop off and replace the impeller (45 min for me).



The impeller materials must not be very good anymore...!

My outboards:

-1972 Johnson 6 hp - original impeller - never a problem.
-1973 Evinrude 115 hp - changed once ~1991 while apart for straightening
the prop shaft.
-1975 50 hp looper - retired in 1986(still have it, though) with
original impeller
-1981 Evinrude 115 hp - not changed since I bought it in 1997.

When I was the tech for a 50-60 boat rental fleet, about 1982 - 1987, we
had all Johnson & Evinrude - lots of 5.6 & 6 hp, 9.5 & 10 hp, 18/20 hp,
many 28-33-35-40 hp, some '76-up 35's, 55-60-65-70 hp loopers, even some
old "pumpkin" V-4's, I cannot recall changing a single impeller.

For two months a year, they never sat still for very long, though.


Rob

Your correct in that they will last a long time. I have gone for long times
as well. It is more of a matter of knowing for sure that your not going to
have a problem.
Rarely do they actually go completely out.
They will over time tend to not produce as much pressure as they should.

Kind of like changing your oil. Some do it 3000 miles, some 5000 miles,
some 7500 miles, some 10000, some 15000, some never. Yet the car still
runs.

Or like timing belts on cars. 90000, 100000, never...

Most change them every 2 to 3 years just as a precaution.


--
Tony
my boats and cars at http://t.thomas.home.mchsi.com
"trainfan1" wrote in message
...
Jeff Rigby wrote:

-VI


Three reasons to replace the impeller with normal use. 1) Dirty water or
idling in shallow water can cause the impeller to wear out prematurely
(sand). 2) The impeller becomes less flexible and can loose it's shape
causing less water flow and poor priming (apx two-three years) . 3)
catastrophic failure because the rubber rotted (Aprox 5+years).

Another good reason to do it often is that the bolts will be easier to
remove.

Outdrives are easier to pop off and replace the impeller (45 min for me).

The impeller materials must not be very good anymore...!

My outboards:

-1972 Johnson 6 hp - original impeller - never a problem.
-1973 Evinrude 115 hp - changed once ~1991 while apart for straightening
the prop shaft.
-1975 50 hp looper - retired in 1986(still have it, though) with original
impeller
-1981 Evinrude 115 hp - not changed since I bought it in 1997.

When I was the tech for a 50-60 boat rental fleet, about 1982 - 1987, we
had all Johnson & Evinrude - lots of 5.6 & 6 hp, 9.5 & 10 hp, 18/20 hp,
many 28-33-35-40 hp, some '76-up 35's, 55-60-65-70 hp loopers, even some
old "pumpkin" V-4's, I cannot recall changing a single impeller.

For two months a year, they never sat still for very long, though.


Rob

On Thu, 21 Apr 2005 23:08:43 GMT, "tony thomas"
wrote:

~~ snippage ~~

Kind of like changing your oil. Some do it 3000 miles, some 5000 miles,
some 7500 miles, some 10000, some 15000, some never. Yet the car still
runs.

I had a Ranger pickup, four cylinder, that I literally beat the crap
out of for the eleven years I owned it. I never changed the oil.
Changed the air filter occasionally., even changed the oil filter once
in a blue moon, but never changed the oil. Can't explain it - once I
got into the habit, I just didn't. I punched out the catalytic
converter at about 90,000 miles when it got a bit clogged up.

It passed emissions every two years - no problem - great numbers.

Go figure.

Later,

Tom