Hot tell tale water

scottie9656

Cadet
Joined
Aug 1, 2024
Messages
9
I just bought a 1981 9.8Hp mercury V.I.N. # 5881663. First thing I did was change the impleller, thermosat and rebuilt the carburetor. First round in the test tank it started up fine but only a few spurts of water and exhaust through the tell tale. I shut it down right away. After doing some research on here I removed the powerhead and found the plastic washer between the motor and water tube was melted. Replaced that. Now if have a pretty good flow of water at idle and a strong flow when in gear. The tell tale water is extremly hot. Could I have a blown exhaust baffle gasket causing it? Motor has only been ran in fresh water.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,722
I have seen that melted washer many times.----Perhaps there are pieces of impeller stuck somewhere.
 

scottie9656

Cadet
Joined
Aug 1, 2024
Messages
9
Could be. When I opened it up the impeller was in one peice. I made sure there wasn't anything from the powerhead down to the pick up screen on the bottom of the foot. The water from the tell tale comes right off the top of the thermstat housing. Themostat is 143 degrees not sure should be hot or not proably 120 degrees.
 

scottie9656

Cadet
Joined
Aug 1, 2024
Messages
9
Could be. When I opened it up the impeller was in one peice. I made sure there wasn't anything from the powerhead down to the pick up screen on the bottom of the foot. The water from the tell tale comes right off the top of the thermstat housing. Themostat is 143 degrees not sure should be hot or not proably 120 degrees.
Well after doing more research I bought a pyrometer to check the engine temperature. After letting it run in a tank in gear for about thirty minutes no part of the engine got over 150 degrees. checked the outlet water and it ran between 120 and140. It appears that some models of this engine have thermosats and some don't. If it has a thermostat the outlet water will be hot.
 
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