engine overheating

Had the boat out on sun. and as it was idling a loud steady tone began sounding. I assume this is the alarm for overheating. I’ve had a boat for over 10yrs now and have never heard this before, guess I’ve been lucky. Shut the motor off waited a couple minutes started again and no sound, motored to another area and as we began idling down the alarm goes off again, give it a little throttle and shortly after the alarm stops. Like this all day, idle and alarm, throttle it and no alarm. Water pump getting weak? Going to take it in anyway but would be nice to go in with some sense of the problem rather than going in blind and saying heres my money take it. been very fortunate in the past as far as marine problems go so I dont really have a good mechanic lined up that I can go to and be 100% sure I’m not getting jacked.

Time to replace the impellar, she ain’t getting enough water.

Is it even “peeing” out the hole??? I had this happen one time on the River in the Spring and got some debris that clogged the “Pee Hole”. Used the kicker to get back to the ramp and on the trailer becasue I had no idea. Got home and figured it out!

Sounds like Dan might also have the Solution.

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Time to replace the impellar, she ain’t getting enough water.

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What he said!

Is it even “peeing” out the hole???

I,m sorry just had to laugh at that one LR.

But,that is what I call that hole too,the “pee hole”

The 3 most likly causes have all been listed. Although your impeller and or water pump should have gone bad about 5 years ago.
If the pee hole is clogged, a bottom bouncer will always do the trick, you will always find one in the splashwell of my boat.

The alarm could also be a low oil sensor if the motor is a 2 stroke, your float could be stuck. You should try to look it up in your owners manual, sometimes one steady beep means something, and a few short beeps means something else.

yes it is still peeing although it never has peed real good just kind of dribbles we have to clean it out all the time just to get a dribble. looking for the manual now

WE SHOULD FIND OUT …
A–MAKE OF MOTOR
B–YEAR
C–TILLER OR STEERING WHEEL
THIS WOULD HELP TO NARROW THE POSSIBILITIES.
SOME ENGINES HAVE STRONGER WATER PUMPS THAN OTHERS. AND THOSE STRONGER PUMPS MIGHT LAST 10 TO 20 YEARS. AND IT COULD BE AN ELECTRICAL TEMP SENSOR IN THE HEAD THAT IS STARTING TO GO BAD! JUST SOME IDEAS.

can’t find my manual 1998 mercury 40hp 2 stroke, steering wheel, thanks so far for the ideas

I agree, time for new impeller. The steady “Beeeeeeeeeep” is the overheat alarm. The “Beep – beep – beep – beep” is the low oil alarm.

When you increase RPM’s you spin the impeller faster and it gets the water up to the top of the motor head where the sensor is and silences it. Slow down, less water to the top of the motor, sets off alarm. Keep this in mind, when water is not in the cooling system it is replaced by air. Hot, wet air quickly turns to steam and shoots the temp up. Not good but not the end of the world either. In other words, you could probably run that motor wide open all day, no problem. Just don’t slow down!

New impeller as soon as possible. When they get old, they go fast.

-J.