Tattle tale temp?.

Elmer Fudge

Lieutenant Commander
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Aug 25, 2003
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1,881
89,75HP Mariner,engine idles and runs great,tattle tail is strong and it stays strong right from 2 seconds after ignition, but it never gets hot, not even luke warm,that's after running for over 45 minutes straight at an average of 4000 rpm.Is their an optimum temperature that this motor should be running at?.
 

bryanredfish

Petty Officer 2nd Class
Joined
Apr 22, 2002
Messages
182
Re: Tattle tale temp?.

My 2002 Merc 90 does the exact same thing. It runs great, however. My mechanic said my model, in particular, is a cool-running engine. It gets somewhat lukewarm after about 15 minutes on the hose, but never even close to hot. As long as it's not over heating, I don't think I'd worry about it. It's obviously a thermostat issue though, and can easily be checked out.
 

profish00

Petty Officer 3rd Class
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Jul 18, 2003
Messages
91
Re: Tattle tale temp?.

does the water run through the heads and Tstat's before it comes out the teltale?
 

Elmer Fudge

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1,881
Re: Tattle tale temp?.

I'm thinking if the water is not passing through the heads and thermostat, would the engine not over heat?. It seems to stay barely warm, I can place my hand on the block and leave it there for as long as I want to. Could this "thermostat issue" be a faulty thermostat?. since it's not or does'nt appear be to overheating in any manner ,what foreseeable problems if any could i expect if i leave it as it is?.. :confused:
 

steam_mill

Chief Petty Officer
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Jan 16, 2002
Messages
413
Re: Tattle tale temp?.

2003 Merc 90 Classic also exhibits the same behaviour. My telltale only ever gets a little bit warmer than than the lake water. Stream is strong. It got week once and I had to blow it out with compressed air.<br /><br />My block gets warm. After running for 30 minutes it is warm to the touch. I can touch it but would not want to hold my hand there for very long.<br /><br />Tx<br /><br />Joe
 

Elmer Fudge

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Aug 25, 2003
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Re: Tattle tale temp?.

Today i spoke with a fellow boater that i met on the lake ,he suggested that i may be running without a thermostat which is very common here in texas, :confused: :confused: well that's the first time i've heard of that.I am going to check and see if i am running with or without a thermostat ,when i get off from work this evening. Question: Why have a thermostat if as it seems by some that it is not all that necessary?. :confused:
 

gss036

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Jan 18, 2003
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2,914
Re: Tattle tale temp?.

I guess! the best answer is, check a parts manual and see if it came with one. Then logically, if you run cold while idling,trolling etc, I suspect you will foul your plugs. I know there are people who take them out. If the thermonstat is working properly then your engine will run better. Would you take the thermostat out of your car/truck? I don't think so. :rolleyes:
 

MrWick

Seaman
Joined
Oct 2, 2003
Messages
69
Re: Tattle tale temp?.

I hate to ask a dumb question,there is a thermostat?Do all Mercury outboards have a thermostat and if so where is it located.The stream coming out of my 85 Merc 115hp inline 6 is nice and warm but I never thought about there being a thermostat.
 

The Marine Doctor

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Jul 25, 2003
Messages
2,177
Re: Tattle tale temp?.

The telltail does not pass through the T-stat. That is why it will be colder water than what is discharged from the engine.<br /><br />When you start the engine, you do not get water discharged from the Upper driveshaft housing until the t-stat opens.<br /><br />If the Telltail worked the same way...there would be no water flow until the t-stat opend.<br /><br />TMD
 

Elmer Fudge

Lieutenant Commander
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Aug 25, 2003
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1,881
Re: Tattle tale temp?.

Other than the tell tale where else is water discharged?.
 

steam_mill

Chief Petty Officer
Joined
Jan 16, 2002
Messages
413
Re: Tattle tale temp?.

Marine Doctor,<br /><br />That makes so much sense. No flow through the block until the t-stat opens. That's why it's cold.....<br /><br />I think the water come out the prop?<br /><br />Tx.<br /><br />Joe
 

The Marine Doctor

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Jul 25, 2003
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2,177
Re: Tattle tale temp?.

Exits out through the prop. This cools the exhaust.<br /><br />Water is going through the block...just not a huge amount. There is a bypass at the T-stat.<br /><br />TMD
 

Elmer Fudge

Lieutenant Commander
Joined
Aug 25, 2003
Messages
1,881
Re: Tattle tale temp?.

Well the engine has a T/stat but I could'nt tell if it was functioning the way that it is suppose to,so i will go ahead and replace it and moniter it's behaviour.Along with the T/stat i also ordered a water pressure gauge kit,if i encounter any difficulty during installation you bet i know where to seek the best advice.Many many thanks to all, you have my sincere gratitude.
 
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