1984 Mercury 9.8 Question

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Mike Stroz
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Joined: Mon Apr 06, 2015 10:52 am
Location: Massachusetts

1984 Mercury 9.8 Question

Postby Mike Stroz » Mon Apr 16, 2018 7:37 pm

Just got this 9.8 up and running. I replaced the water pump but I didn't see any water squirting out anywhere. Is there a "pee hole" (can't think of a the right word) on this motor? I only ran it for a minute since I didn't see any water coming out.
When in doubt, duct tape!

david bartlett
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Location: Western Maine

Re: 1984 Mercury 9.8 Question

Postby david bartlett » Mon Apr 16, 2018 8:28 pm

I think this one has a thermostat, so the tell tale hose should come off the thermostat housing and out through the lower pan. The Merc guys will be along and clarify.
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BillW
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Location: Cape Cod MA

Re: 1984 Mercury 9.8 Question

Postby BillW » Tue Apr 17, 2018 6:05 am

It seems to me like some had the thermostats and some didn't. If it has one, there will be an obvious gizmo with a spring device, to hold it in, near the top of the power head. If it has a thermostat, they were very prone to plugging up with corrosion, in that area. Either way, there IS a peep hole, or tell tale. I want to say it's on the starboard side of the lower cover but I can't remember. Maybe port. It will have a 1/4" black hose coming from the top of the power head, or the thermostat housing. If you have a thermal sensing gun, it shouldn't get any warmer than 160, even with a thermostat. If you don't have a gun, run the engine and put a few drops of water on top of the power head. If it boils, stop; you have a problem.

With these engines, it is not easy to MISS the water tube going into the pump; but it is very easy to BEND the water tube, so that it will not go completely INTO the grommet on the pump. But let's see if you are actually over heating or not.

Mike Stroz
Posts: 185
Joined: Mon Apr 06, 2015 10:52 am
Location: Massachusetts

Re: 1984 Mercury 9.8 Question

Postby Mike Stroz » Tue Apr 17, 2018 7:37 am

Ok, I'll look it over this weekend and see if it has a thermostat. If it does have one, I'm going to assume it's stuck based on the corrosion on the rest of the motor. Is it ok to just remove it entirely?
When in doubt, duct tape!

Fifty20ne
Posts: 80
Joined: Sat Mar 19, 2016 4:22 pm
Location: Toledo,Oh

Re: 1984 Mercury 9.8 Question

Postby Fifty20ne » Tue Apr 17, 2018 4:24 pm

Per MarineEngines it has a thermostat.

http://www.marineengine.com/newparts/pa ... m=MER75692

Jerry Ahrens
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Location: Lake of the Ozarks Mo.

Re: 1984 Mercury 9.8 Question

Postby Jerry Ahrens » Tue Apr 17, 2018 8:05 pm

Mike Stroz wrote:Ok, I'll look it over this weekend and see if it has a thermostat. If it does have one, I'm going to assume it's stuck based on the corrosion on the rest of the motor. Is it ok to just remove it entirely?
If it has a thermostat and you leave it out, the motor will not warm up. This will cause rough running and spark plug fouling. If it is supposed to have a T-stat, be sure to put one in.
Jerry Ahrens AOMCI Member MAPS Chapter President

Mike Stroz
Posts: 185
Joined: Mon Apr 06, 2015 10:52 am
Location: Massachusetts

Re: 1984 Mercury 9.8 Question

Postby Mike Stroz » Sun Apr 22, 2018 2:19 pm

I don't have time to work on it this weekend, but I looked and my motor doesn't have a thermostat. I can see where that hose goes and there wasn't any water coming out when I ran it. Clogged hose? 99% sure I did the water pump right and everything sealed up tight
When in doubt, duct tape!

BillW
Posts: 799
Joined: Sat Apr 11, 2015 6:35 pm
Location: Cape Cod MA

Re: 1984 Mercury 9.8 Question

Postby BillW » Sun Apr 22, 2018 4:38 pm

See again my first post in this thread. If nothing there helps, remove the lower unit and try to blow through the water tube BY MOUTH, with a piece of hose attached. With no thermostat, you should be able to blow through with only a little effort. The blocks do plug up sometimes...

Mike Stroz
Posts: 185
Joined: Mon Apr 06, 2015 10:52 am
Location: Massachusetts

Re: 1984 Mercury 9.8 Question

Postby Mike Stroz » Sun Apr 22, 2018 9:19 pm

Ok, I'll check that when I get a chance
When in doubt, duct tape!

Dougs Outboards
Posts: 120
Joined: Fri Mar 20, 2015 1:39 pm

Re: 1984 Mercury 9.8 Question

Postby Dougs Outboards » Mon Apr 23, 2018 2:27 pm

Mike,

Please try this first:

While the motor is running in a barrel, simply take your air hose and squirt a 1-2 second blast of air tightly into the pee hole from the outside where the water is supposed to pee out. It should start peeing in a second or two if there is no problem. It breaks up the crud plug and rinses it out of the little end on the tube and such. Has worked many times for me, even after installing a new impeller.

Whaddaya got to lose, only takes a second...


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