temp guage or alarm

81_chapparel194

Petty Officer 1st Class
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Aug 7, 2012
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341
ok my boat has a 90 hp o/b 1981 model evinrude and i dont have a temp sensor nor alarm (that i know of) so whats best to know when i overheat??? i would prefer a guage so i can tell BEFORE it gets too hot and ruins an engine... i dont even like the idiot lights on most newer cars... my requirements for a vehicle is to have a temp and oil pressure guage... my 08 dodge ram 1500 has all that plus a trans temp guage also very helpful when pulling... i know these are electric guages but still better than a light that waits till its too late to pop on.... but my question is do they make a temp guage for my motor? and will the aftermarket temp guage from say an auto parts store work on the boat if i install it into a water jacket? and whats normal operating temps for my motor????
 

UncleWillie

Captain
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Oct 18, 2011
Messages
3,995
Re: temp guage or alarm

You want an alarm as the primary device.
After the alarm sounds look at the gauge.
The gauge will only alert you if you are looking at it.
A hard running engine that suddenly blows an impeller will overheat in 60 seconds.
No one looks at the gauges that often.
 

81_chapparel194

Petty Officer 1st Class
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Aug 7, 2012
Messages
341
Re: temp guage or alarm

how can i tell if my motor has a sensor and if it works???? as i said its an 81 90 hp evinrude v4 i constantly watch the pee stream from the engine... but i want to know what my engine temp is... and believe it or not i am constantly scanning my guages just a sin my truck... about 60 seconds with no oil pressure at hiway speeds and engine is ruined... it only takes a second to scan the guages.... do you think a pilot in a jet doesnt watch his guages..and if your not a guage watcher you SHOULD be... i would hate to say "if i had only watched my guages i wouldnt have a fried engine" but anyway thats just me... i would like an alarm BUT a guage also.... alarms fail so do guages but they cant fail if they arent on there...
 

Bondo

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Apr 17, 2002
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71,417
Re: temp guage or alarm

Ayuh,.... On Outboards, a water Pressure gauge will tell ya what the impeller is doin'....
 

81_chapparel194

Petty Officer 1st Class
Joined
Aug 7, 2012
Messages
341
Re: temp guage or alarm

Ayuh,.... On Outboards, a water Pressure gauge will tell ya what the impeller is doin'....
i can see what its doing as i watch the pee stream from engine..i want to know the operating temp of the engine...
 

acarter92

Petty Officer 2nd Class
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Dec 25, 2011
Messages
198
Re: temp guage or alarm

An alarm, whether on a car, truck, or boat doesn't go off when it's too late, or it would be useless. They are ment to go off before it's too late. I agree a temp guage would be nice but if I had to choose one I would pick an alarm.

Just my 2 cents,
Austin
 

81_chapparel194

Petty Officer 1st Class
Joined
Aug 7, 2012
Messages
341
Re: temp guage or alarm

Ok I am seeing the need for an alarm. But want a gauge too. Main question is WHERE is the alarm and how do I know if my boat has one? Where would I look and how can I test to make sure it works?
 

UncleWillie

Captain
Joined
Oct 18, 2011
Messages
3,995
Re: temp guage or alarm

Not familiar with your particular motor.
If it is a four stroke and has an alarm, the low oil pressure and the high temp are usually connected to the same sounder.
The alarm would sound with the Ignition ON before starting as there is no oil pressure to silence it.
If you have an alarm, it would sound before it starts?
 

jigngrub

Fleet Admiral
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Mar 19, 2011
Messages
8,155
Re: temp guage or alarm

i can see what its doing as i watch the pee stream from engine..i want to know the operating temp of the engine...

Watch what's in front of you and where you're going, not your tell tale.

Change your impeller every year or 2 years for peace of mind, learn how to do it yourself an it's only $20. Lots of vids on youtube.

I agree with installing the alarm and gauge, 2 are better than 1.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,946
Re: temp guage or alarm

On gauges vs idiot lights, aka automobile oil pressure and alternator lights, I'll take the gauge any day, due to your being able to see what's going on.....course you have to look at it to do any good.

Mark
 
Joined
Oct 22, 2007
Messages
2,598
Re: temp guage or alarm

That engine should have an overheat alarm, go to the top of this forum, top secret files, free wiring diagrams.

I also have an '81 90 HP engine, and when I get home tonight (if my old-fart brain can remember) I'll look in my factory service manual to verify the wire color. The free diagram shows the wires for the temp alarm being black/white, I was thinking they were brown but I might be wrong on that (I know they're brown on my '90 200, and the black/white is for fast-start).
 

Bama Hound

Seaman Apprentice
Joined
Jul 30, 2012
Messages
47
Re: temp guage or alarm

Ok I am seeing the need for an alarm. But want a gauge too. Main question is WHERE is the alarm and how do I know if my boat has one? Where would I look and how can I test to make sure it works?

I hear you brother! I am like you I have an OCD (obcessive compulsive disorder) for scanning instrument panel. On my boat I have a closed circuit tv with a camera mounted on the deck above transom aimed at the pee stream. Another camera shows aft to view approaching traffic. It ain't exactly excellent entertainment on a 6" B/W screen, but it gets the point across.

If you order a gauge, which I did on a previous boat, it will come with instructions on how and where to mount. Mine required removing one of the cylinder head cover bolts and placing a "L" shaped bracket that held a sensor, that made contact with the head. One of the problems you will have to consider may be looks. Do you have a problem with the gauge faces not matching in color and degree of hand sweep? If you don't, you can hang an after market bracket below dash, or somewhere it isn't a "knee knocker". You can buy a cheap hole saw and mount it in existing dash. If you are handy, you can make a new dash with matching colored faces and bezels on the gauges. You can add more gauges and make a gauge watcher utopia.

My eyes are constantly moving between rear view mirrors, CCTV, instrument panel as well as oncoming traffic. Never in one place. In my case, I rear mounted CCTV's with microphones built-in, (they were intended to be security cameras), I open mics when I am starting motor and occasionally while underway just to monitor sound of motor. Maybe there are enough of us out there, to start a group. Sounds like this, " I am Bama Hound and I am a gaugeoholic". Good luck fellow suffer.
 

81_chapparel194

Petty Officer 1st Class
Joined
Aug 7, 2012
Messages
341
Re: temp guage or alarm

you sound a lot like me as for being aware of your surrounding and such... i havent went as far as the cctv but again i am only running a 19 ft bow rider .... but i am the type i want to know i have a problem while its still repairable and before it pukes... if i notice my truck guages a little out of the norm i stop and check for the problem BEFORE the needle pegs out and the engine is seizing up...i know my engine sounds and i know when something doesnt sound right... being a mechanic most of my life i pay attention to this kind of stuff... and for guages goes bama hound i currently have black face guages with orange needles so the sunpro aftermarket guages are offered in same color scheme... and i have room to pop a hole in my dash panel for the temp guage and a few other.. probaly get me a voltage guage as well to measure my voltage.. i have seen the ones that plug into a power accessory outlet and give a reading but i think i will get the guage in the dash.. i do need a camera pointed at my drain plug tho as i am so worried one day i will forget it.. but thats why i keep it in my cup holder right by my helm i would see it instantly when i step foot in the driver seat.. if its not there its in the transom where it belongs..
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: temp guage or alarm

Your engine already has an over heat sensor on it. #35 is the sensor, located in the cylinder head. It should have a tan or brown single wire going to it, slide the rubber boot back to expose the knife connector, seperate the wires. Turn the key to the ON position, touch the wire end from the HARNESS to the block to ground it and the horn in the control box should sound off.
http://www.ishopmarine.com/ishop/js...nown&isFrPG=false&forItemCode=&pCode=C0222811
 

81_chapparel194

Petty Officer 1st Class
Joined
Aug 7, 2012
Messages
341
Re: temp guage or alarm

Your engine already has an over heat sensor on it. #35 is the sensor, located in the cylinder head. It should have a tan or brown single wire going to it, slide the rubber boot back to expose the knife connector, seperate the wires. Turn the key to the ON position, touch the wire end from the HARNESS to the block to ground it and the horn in the control box should sound off.
http://www.ishopmarine.com/ishop/js...nown&isFrPG=false&forItemCode=&pCode=C0222811
ok i grounded this wire to the block it was a tannish brown color touched it to engine NO sound... maybe the horn is bad??
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: temp guage or alarm

Did you try and ground it to a painted surface, maybe you didn't get a good ground? You did have the key in the ON position didn't you?Either the horn is defective or the wires going to it are defective. You need to open the control box and use a volt meter or test light to check the system.
 
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