Outboard overheating..... help
#1
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Joined: Sep 2007
Posts: 2,571
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From: Gaylord, Mi
OK dont razz me to hard on this one.
I have a 1964 Johnson 90 hp that over heats. I pulled the water pump off and the housing and impeller look fine. Checked the inlet screen and totally clear. Plulled the thermostat and still same problem. Drove it to the launch thinking my boot and bucket maybe were not sufficient and still no go.
Bottom line is water is just dribbling out of the exhaust hole and I am stumped. Keep in mind that this is a new motor to me and I have just about zero experience with outboards. Also when I pulled the carb and took it apart it was totally full of Sh!t!. Im guessing the thing hasnt run in 10 years. Runs good now but is just overheating. Help
I have a 1964 Johnson 90 hp that over heats. I pulled the water pump off and the housing and impeller look fine. Checked the inlet screen and totally clear. Plulled the thermostat and still same problem. Drove it to the launch thinking my boot and bucket maybe were not sufficient and still no go.
Bottom line is water is just dribbling out of the exhaust hole and I am stumped. Keep in mind that this is a new motor to me and I have just about zero experience with outboards. Also when I pulled the carb and took it apart it was totally full of Sh!t!. Im guessing the thing hasnt run in 10 years. Runs good now but is just overheating. Help
#3
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Joined: Aug 2006
Posts: 4,200
Likes: 1
From: Simsbury ct
I know merc manuals tell you to account for EVERY piece of a burned or broken impeller because they can clogg the chanels in the block and cause hot spots in the engine.
Not sure if this is in anyway related to, your problem though.
do us a favor and if you find the problem come back and post so it helps out someone else in the future.
also not to bring in another site buy screamandfly.com has lots of OB knowledge
Not sure if this is in anyway related to, your problem though.
do us a favor and if you find the problem come back and post so it helps out someone else in the future.
also not to bring in another site buy screamandfly.com has lots of OB knowledge
#4
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Joined: May 2011
Posts: 41
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From: Iowa
it could be a mud dauber nest or some other debris in the telltale just not letting the water out. are you sure its actually getting hot?
used to happen to me all the time if i got into a little mud.
try poking a little wire or something in there and see if more water comes out,
used to happen to me all the time if i got into a little mud.
try poking a little wire or something in there and see if more water comes out,
#6
As others have said, assuming your impeller is actually still good and pumping water, you need to make sure what's going in is actually circulating fully and getting back out. My Merc overheated once when I sucked a stone up and it lodged up near a thermostat on one bank. Back flushing popped it right out.





