T.R | Title | User | Personal Name | Date | Lines |
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521.1 | | AITG::KARR | | Tue Sep 26 1989 10:27 | 13 |
| I have a 65 evinrude..60hp... Although I have not had an overheating
probelm with mine, When I first got the boat, I put a new impeller
in it.. I suspect this is your problem... It could be burnt out or
simply worn to the point where its not functioning.
If the engine was ever run without water or a hose hooked up, this would
definately burn it out... I have a full (original) service manual for
mine and will lok up the flow of cooling. (johnson and evinrude are
the same engines (basically) and the years are not that far off) its
worth a 'look see'...
stay tuned...
rak
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521.2 | A common Mercury problem? | NRADM::WILSON | A man's place is on his boat | Tue Sep 26 1989 10:35 | 5 |
|
This sounds very similar to the problem Colin Mackey had with
his Merc 75. See note 479 for further info.
Rick
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521.3 | I'se Been There Too | TIS::GRUHN | | Tue Sep 26 1989 10:43 | 40 |
| I think I have had this problem myself! This summer I put in service
a 1958 35 horse Johnson that I had been restoring over the previous
two years. The thing is a fresh water motor that had been used by
the previous owner as a source of parts and proved to have low miles
and no visible wear on the cylinder walls or corosion. After replacing
all the missing pieces it ran like a watch and started on one or two
pulls, but wouldn't pump water despite a new impeller. The first thing
I did then was to take off the bottom end, build an adaptor so I could
run the driveshaft from an electric drill and submerge the bottom end
in a tank of water. It pumped just fine. BTW last year when I first got
it running I had all kinds of trouble getting it to pump until all of a
sudden it started on its own. This year again. Now that I saw the pump
working, I took a coathangar wire and rodded out the water tube to the
power head. A friend of mine on Cape Cod has had problems with little
spiders getting into the water tube and making their webs which make a
nearly waterproof plug. (I've had this happen on my gas fired space
heater pilot light at the Cape). This fellow reams them out and
flushes the motor with water under pressure from his garden hose. Well
now my 35 HP is far too old to have a gardenhose fitting so, while the
bottom end was off and the rodding was done I fitted up a garden hose
to the water tube and flushed the thing under pressure. No problems
showed up, but the spiders could have been busy. Next I put the bottom
end back on the motor and fired it up. Boy did that engine pump water.
And it did so for the rest of the season which amounted to 4-5 weeks
of use. What was the problem? I haven't a clue. You know what it took
to get it going. One old timer who runs a marine shop and repairs
OB's said that those old timers were hard to prime after extended
periods of non use. Another repair shop on the Cape said that I should
replace the entire water pump, that most people make the mistake of
replacing only the impeller. IMO he was just trying to sell parts, but
that is opinion only. It runs now. we shall see what hapens next
season. If anyone out there has any more or better information, it
looks like there are at least two of us who would like to hear it.
One other input from another dealer concerned the rubber fitting at
the top of the water tube. He said that oft times it gets shrunken
and distorted and blocks the water flow to the power head. My probing
with the coathangar didn't indicate this to be the case but it could
be on your motor. Good Luck and lets hear the outcome please.
Bill
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521.4 | Restriction in top end | BIZNIS::CADMUS | | Tue Sep 26 1989 13:36 | 41 |
|
With ethese old Motors- it can be a number of things- I have had a
couple of dozen different motors I've torn down over the years with
pumping problems- here is what I would look for:
1. The key in the inpeller falling off/out during assembly
2. the bottom plate installed incorrectly or upside down
3. salt/corrosion plugging up the power head- the water dischrge paorts
under the exhaust cover should be checked.
4, corrision compressing the run=bber groimmet where the water tube
goes into the power head.
5. spiders, etc.
6. worn pump housing/seals.
7. restricted water inlet screen
8. Water tube not aligneing with bushing in lower unit
9. rubber bushing for water tube collapses when installing lower unit.
The other thing I'll admit to is that these old OMC motors just don't
want to pump after being stored. I've had all kind of problems and then
all of a sudden it will pump like afire house- it seems to be ok after
it gets a "prime".
If you have checked out the pump by turning the drive shaft with a
drill and it pumps- get into the water inlet tube- if it looks like
it's restricted wher it goes into the power head- the rubber grommet or
bushing may have closed off- you can push a coat hanger through, but
enough water often won't get by beacuase the rubber is all mushed
together..
If you have eliminated the lower unit/water pump- then I'd pullthe
power head and check the water discharge ports and replace the rubber
grommet/bushing where the water tube goes into the power head. I'd also
replacethe rubber bushing where the water tube goes into the lower
unit. These O(&%$^^&_ bushings have been a source of trouble on a 15, a
40, and an old 75 johnson that I had.
Hope this helps.
Dick
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521.5 | Impellor housing should be round like an O, not flat like a D | ULTRA::BURGESS | | Tue Sep 26 1989 13:52 | 10 |
| re .0 If the pump housing is not perfectly round you may have
trouble getting good flow and/or good pressure, at which point all of
the previously mentioned sources of blockage or suction leakage will
become more critical. So, why would the impellor housing get out of
round ? {Simple dear Watson (-:} frost/ice can push in on it from the
outer cavities. I have an unofficial fix, but you would need to
perform it on a replacement housing.
Reg
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521.6 | Mine was a bad housing | ATSE::GOODWIN | | Wed Oct 04 1989 12:08 | 0 |
521.7 | Mine needed a new impeller housing | ATSE::GOODWIN | | Wed Oct 04 1989 12:16 | 29 |
| I had the same problem and it turned out to be the pump housing.
It was an old Johnson with an aluminum pump housing and a worn
impellor. When I tried the electric drill trick, it would push water
only about a half inch out of the tube, which wasn't enough to get up
through the power head and cool it.
I noticed that if I put my finger partly over the tube, then the
pressure would increase and the water would shoot up a couple of feet.
But as soon as I took my finger off, it would graduall fall back down
again.
I went for a new impeller, and the show owner told me it would be about
$30. I was going to get it, then he asked to look at the pump housing,
which I was holding in my hand. He said that the housing was pitted
and ought to be replaced too. I had sanded it fairly smooth with emory
paper, and figured he was looking for more money, but he explained that
the seal between the housing and the impeller was critical for the pump
to work right.
I asked him just for laughs what a replacement pump kit would cost
(impeller, plastic outer housing, stainless inner housing, gasket,
rubber tube seal, bolts). He said $29.
So I bought it and she pumps water like old faithful now.
Good luck with yours. Hope this helps.
Dick
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