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1990 75 hp mercury outboardHELP

J

jasonjmw

New member
"hi all I'm new to the sit

"hi all I'm new to the site an have a few questions.

I have a '90 75HP merc.
I have had a constant beep(tone) I can't figure out.
When motor is running I have water coming out the telltale(pee hole) and if I touch the case on the head it is warm but not hot. I can keep my hand there.
Motor runs great other than this constant beep(tone) and it is obvious it is not overheating or I'm sure it would be fried by now.

What parts do I need to change to make this stop?
How much will the parts cost roughly?
Where can a buy a repair manual for this motor?
thanks in advance for any help
"
 
"Jason, you could simply have

"Jason, you could simply have a bad temp sensor. They are a simple design that can and does fail.

At least when they die you get an alarm - better than "not" getting an alarm, assuming everything is fine and when you really do have an overheat, you fry your engine because you didn't know.

I believe your temp sender is located just below the thermostat and poppet housing (near the top cylinder on the head). It should have a black wire coming from it that goes down to a little block with a stud or two on it.

You can try simply disconnecting that black wire and if the alarm goes away, then you know it's the sensor that's bad.

A new sensor sells for about 50 bucks at a Merc dealer.

For a Manual - if you want a Selocs (decent), you can get one from this site - right side of the page..."
 
If it was a sensor wouldn'

If it was a sensor wouldn't the alarm sound as soon as I start the motor?
Last time I was out the alarm started after about 20-30min of run time.
Thanks for your help Graham
 
"I'm leaning towards just

"I'm leaning towards just replacing the sensor, and poppet valve.

What are the symptoms of a bad/faulty poppet valve??

Also does anyone have a diagram or PDF they could send me of how to replace these?

Thanks"
 
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