Tell-tale water is very hot

Claude75

Cadet
Joined
May 19, 2003
Messages
21
Hello Everyone, this is my first post to this board. <br /><br />I have a problem with my 1985 Mercury 75 HP.<br />1. When running out on the water, I touched the tell-tale and the water coming out of it. Is very hot. Enough that I can touch, but I probably could not hold my hand there for a long time. <br /><br />2. At Neutral, to just in gear it seems to spit the water out of the tell-tale but it is not by any means a constant stream.<br /><br />3. Is there a thermostat on this engine that would tell me it is getting hot?
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,762
Re: Tell-tale water is very hot

This is not good.<br /><br />Sounds like your impeller or the entire waterpump needs to be replaced (not enough water flow). You may also need a new thermostat.<br /><br />The thermostat opens and closes to control water flow to maintain optimum operating temperature. <br /><br />If you don't have a temperature or water pressure guage on the dashboard, you might want to consider have one or both installed to help you monitor your engine.<br /><br />I wouldn't run it again until it is serviced.
 

robalofish

Petty Officer 2nd Class
Joined
Apr 3, 2003
Messages
116
Re: Tell-tale water is very hot

Some engines have the tell-tale after the thermostats and the water will be hot, others have the tell-tale prior to the thermostats and the water would be cool and at a higher volume right from the start. Not being familiar with your engine don' fret yet. Although you may indeed have a water pump problem, get more info. I have a 94 200HP and the water comes out at trickle until the thermostats open up and then temp is 140 deg. with a constant flow of water. Do you get a constant flow after warmed up? If not I would defiantly have the water pump changed and thermostat as well. Should be done at min every 2 years. Mine are done every year prior to summer heavy boating season.<br /> <br /><br />RFish >()> :) :)
 

Claude75

Cadet
Joined
May 19, 2003
Messages
21
Re: Tell-tale water is very hot

Hello Robalofish: <br /><br />Actually, the things is the water comes out at full stream, only while the RPMs increase. When in idle it kind of spits the water out. I just bought this boat, so I will go ahead and change the water pump and impeller. BTW what is the difference between the water pump and the impeller, or is it one thing.
 

carmangary1

Seaman
Joined
May 11, 2003
Messages
52
Re: Tell-tale water is very hot

The water pump is the complete pumping assembly, including the case. The impeller is just the thing inside that rotates and pushes the water through the pump. The impeller is the part that wears out.
 

robalofish

Petty Officer 2nd Class
Joined
Apr 3, 2003
Messages
116
Re: Tell-tale water is very hot

Based on your last post I would change the impeller probably best to get the complete kit not much difference in the price this way you get almost everything new in the pump. Also if thermostat not been changed recently change it as well.<br /><br />RFish >()>
 
Top