Mercury Outboard Alarm

Discussion in 'Boating and Boat Rigging' started by HemlockNailer, Aug 1, 2003.

  1. I have 19 ft. Starcraft with a 115 h.p outboard. Last night while towing a larger boat at slow speed an alarm sounded. I had plenty of oil in the injection system and the motor was circulating water. After towing I ran the boat at high speed but it took 10 minutes or more before the alarm stopped. At the dock I shut the engine down and restarted with no trouble, any ideas ? Could it be just a faulty alarm ? I do not have the manual.

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  2. I had one. I noticed you could ski and tube for half a day after it sounded and it was the oil alarm. I guess they want to make sure you were reminded early.

  3. I have a Evinerude 90 horse and my alarms are like this,
    A constant sound means overheat, check your water intake.
    A beep every 20 seconds means low oil, check the oil in your oil tank.
    A beep every 3 seconds means no oil to the motor, squeeze the oil primer bulb and see if it stops.

    I had a "No oil" alarm on my motor at trolling speed and squeezing the bulb would make it stop for about 20 minutes. At higher speeds the alarm would not sound. Turns out my oil injection pump was bad.
    $525.00 fixed it.

  4. i had a 50 horse evinrude all i had to do was pump the ball on the oil line and it shut off.
  5. Ran the motor this morning, everything fine for seven miles at high speed. Started to troll and there goes the alarm again. Felt under the dash to locate a wire to disconnect and the alarm goes off, a short or loose connection right ? Get back to boat slip and find no power tilt or no power to starter, all other electrical seems to be fine. What is going on? By the way we caught four lakers.
  6. Don't know about Mercury, but my Johnson did that...overheating alarm under dash. I replaced the impellar and all has been well. I didn't get the alarm all the time adn i didn't get it at high speeds...and the "pee" stream seemed just fine to me. I usually got it soon after launching and going slow down the river in the no wake zone. I guess sometimes what happens is that at low rpms, if the impellar is worn it doesn't build enough pressure to cool the top cylinders off, but the bottom ones are getting good water. This results in a good stream coming out of the motor, but it's not evident that it's not enough to get to the top cyclinders.

    Be careful disconnecting the alarm...cit ould result in ruining the motor from overheating or no oil. A new motor is a LOT more than fixing a small problem like this one!

    Good luck!

  7. You may be peeing water, but it is not pumping enough. Highly suggest you change the impeller. Don't disconnect the alarm they are there for a reason ( ask my cousin, He blew up his motor). Power problem may be a blown fuse, you may have touched a few things together when you reached under the dash.
  8. Same problem with a Merc. Two fix's: with the horn going off, put your finger over the tattle tail hole for about 20 seconds. If the horn goes off, you are overheating at the sensor. This is at the top of the cylinders, so change out the impeller. Secondly it may be at the inlet tube connection. If you drop your lower unit to change the impeller, look up into the housing. Where the inlet tube enters the head, there is a plastic connector. This connector gets hot and cracks and you loose pressure. Parts can be bought at any merc service site.

    It worked for me.
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  10. I did not even notice this thread was still running,,,I had thought you put in some oil and the alarm went away,,,
    First like SalmonSlayer and Andy Capp said do not unhook your alarm! I mean sure it will be nice to not have to listen to the alarm but think of how peaceful it will be when the flywheel stops spinning!
    Also Spendit is correct most of your big mills cool from bottom to top,so covering the pee tube is a valid test,,also with the motor cover off you can tell a lot by feel,,,you know feel the motor up at the top by the sensor,,is it hot?,,,with that said I will add that if the impeller is more than 2 years old change it!!!! if it is new but the motor has sat for a long time change it!!! I don't care how good it looks when you take it out change it anyway,, I can not tell you how many times I have seen blown powerheads because someone tried to save $20,,,Also I did not think this needed to be said, it should be common sense but I will say it anyway,when you are changing your impeller make sure you are getting a good seal around the impeller housing and that your input tube has a good seal,,,also make sure your water pickup, input tube,tell tale,exhaust or any thing else is not clogged or partially clogged!!
    Also have a look at the stat and it's porting once in a while!!!
    And Wickedcarpenter you are right there are some very sharp fellas over at Scream and Fly,,,I am on that board a lot but I rarely answer any questions because I just don't get the chance!
    I mostly go over there to shop for parts and rap with some people ,,,it is nice to know there are a bunch of people who make me look sane!!!
    I will say if I get a problem with a brand new mill, that is the first place I will look for info because I don't care how new a big mill is,someone over there has already pushed it to the limmit and had it in pieces,,,you know what those guys do to a motor in one run is probably= to the abuse you put on your fishing motor all year if not more!!! Also these guy's think nothing of putting down the cash for brand new motor then ripping it apart and swaping out things like cranks,blocks.gearcases,and many other thing,,what this means is that these guy's have some pretty tasty like new parts just looking for a home!!!!
    Just take what you read over there with a grain of salt,,youknow it's doubtful that your fishing boat needs bigger carbs,ported crank,lightened flywheel,low water pickup,28p chopper prop or a lot of other wounderfull things you might reed about over there!!!!

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