beeping alarm inside throttle box, overheat alarm? 1989 Mariner 115 HP

[exnavyman123]

I went boating this weekend and wasn't running the boat long at all and a beeping alarm sounded from inside the throttle box, i think there was water coming out of the pee hole but don't remember, is this the overheat sensor? I was hoping the temperature sensor was just faulty, and needs to be changed.

2Nd problem : When i had the throttle lever at full throttle (a while before the alarm sounded) the boat would only goes less than half power , the priming bulb was not getting firm when i put it in the water i was told that problem could be vapor lock?

Thanks

 

[exnavyman123]

Re: beeping alarm inside throttle box, overheat alarm? 1989 Mariner 115 HP

29 views and no replies, hoping someone had this happen before .......

 

[CharlieB]

Re: beeping alarm inside throttle box, overheat alarm? 1989 Mariner 115 HP

A solid beeeeeeeeeeeeeep is an overheat alarm, a continious rapid beeping is an oil alarm, either demand your immediate attention.

If the rapid beeping continues/begins immediately as the key is turned ON but the motor not started, it could be an adhesive failure, the magnet on the bottom of the oil tank float falls off, triggering the constant beeping oil alarm. If this is the case, unplug the two blue wires under the oil tank to see if the alarm quits. If so, order a new oil tank.

If this is not the case and it is the oil alarm, add oil to the fuel to a 50 to 1 mix to protect the motor until this is figured out and repaired.

 

[exnavyman123]

Re: beeping alarm inside throttle box, overheat alarm? 1989 Mariner 115 HP

ok, thanks a lot Charlie, i read about my oil resevoir and the magnetic sensor , and the confusing way to fill the resevoir. The manual says that it's pressurized but not sure how to do that i think is my problem. The resevoir looks "sucked in" not sure if thats a bit normal or not. i did fill the tank say about 3 hours worth of drive time before the alarm went off, i filled it on Friday, ran for about 3 hours or so on friday all was good, and on the next trip to the lake putting the boat in after 20 minutes of driving the alarm went off and i went to shore and took it home. from what i read i guess that 3 minutes of puttering back to shore won't hurt i hope.

 

[beckoning]

Re: beeping alarm inside throttle box, overheat alarm? 1989 Mariner 115 HP

I have the same motor in the 100hp version and had a similar problem. I decided to pay a good, certified Mercury mechanic $200 to check the system and replace the sending unit at the motor. As you may well know, that motor has 4 carburetors that really suck the gas (and thus oil) at any rpm over 3,000, so you may have just used up all the oil. I am not aware the oil tank is pressurized, but if it is caved in, it may indicate it is low on oil. As CharlieB suggested, if you put in some oil and start the motor and it is squirting water to show it is cooling, and still does the intermittent beep, you need to replace the tank or pre-mix oil in the gas and disconnect the wires. I decided to spend the money to have things checked out by a competent mechanic and am glad I did.

 

[howardtwo]

Re: beeping alarm inside throttle box, overheat alarm? 1989 Mariner 115 HP

do you have a water pressure gauge and does the alarm only sound at slower speeds and goes off at a faster pace. I had this proplem and it was low water pressue (bad water pump)

 

[Rubycon]

Re: beeping alarm inside throttle box, overheat alarm? 1989 Mariner 115 HP

I have a Merc 50 four stroke that began beeping.
One beep 1 min. after startup with three beeps 10 mins. later and two beeps 5 mins after that. Repeated after startup.
Turned out to be a voltage regulator that was charging the battery past 15 volts.

 

[exnavyman123]

Re: beeping alarm inside throttle box, overheat alarm? 1989 Mariner 115 HP

Thanks all, turns out it was the oil tank, the 3 inch sensor mounted in the bottom of the oil tank was loose, meaning i could pull it down and push it up, the oil tank was about 3/4 full , when i pulled it down and pushed it back up the alarm stopped and started ( stopped when i pulled it down). I pulled it all the way out with oil in the tank and it has a rubber cover on it that had a cut in it, i took a razor blade and cut the rubber away to see what was inside and it was a glass tube with a wire in it and the glass tube was broke, i ordered a new tank and sensor(sold seperately) and ordered a new oil control module as well. I replaced the water pump and thats working great. Only thing i didnt like about the repair manual was that it didnt explain how to replace the bottom of motor with the drive shaft(the short spined shaft) in neutral instead of in gear, turns out just turn it until the prop spins free in both directions. Do i need to do anything speacial after removing old tank and replaing it with the new ( bleed the oil line, etc) ? I decided to replace both the tank, it's sensor and the oil module and then after running it remove the oil hose from the outlet of the oil pump to verify it's pumping, and the see what beeps i get when all is working correctly, does anyone know the series of beeps that should sound?

 

[dougie66]

Re: beeping alarm inside throttle box, overheat alarm? 1989 Mariner 115 HP

Hey CharlieB
Just letting you know your thread is still solving problems. Thanks for your reply to the thread here as it has also helped me. Now I just have to fix my outboard.

NB being an aussie I didnt know the answer to the random question "Smallest State in the USA" so I have now learnt two things lol