1999 40hp Yamaha alarm going off

Discussion in 'Bubba's Outboards' started by turkeyman, Jul 7, 2008.

  1. turkeyman

    turkeyman New Member

    Messages:
    22
    State:
    South Carolina, Swansea
    Everything runs good, and the thermostate and water pump were replaced 1 1/2 years ago. The alarm will go off when I get on plane. It can run all day not on plane and no alarm. The Strange thing is that is does not do this all the time, just most of the time. Help Please!!:big_smile:
     
  2. BailBonds

    BailBonds New Member

    Messages:
    282
    State:
    Indiana
    Check your oil reservoir mount. Got stranded several miles off shore because of one. It was tilted showing low oil warning. The real brains will pick this up pretty soon.
     

  3. turkeyman

    turkeyman New Member

    Messages:
    22
    State:
    South Carolina, Swansea
    Thanks, maybe it is a 1998 motor. I have to premix. This motor doesn't have a oil resivoir, I think. I don't know much about 2 strokes. I think the motor only has a overheating alarm. Forgot to mention if I slow down to idle or close to idle the alarm goes off. I was kind of thinking the thermostat was bad or the water pump was bad.
     
  4. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Don't know about the alarms on Yamaha's, but I can almost guarantee you that if that is the water temperature alarm going off, your gonna have a damaged engine fairly soon. Make sure you replace that water pump assembly and impeller. It is less than $40.00 for the parts and you should be mechanically inclined enough to replace the parts. I don't know of another alarm on those motors. It could be the impeller and pump are okay, and the problem is with the thermostat or a blockage in the water circuit. But start with the most obvious (Pump and impeller) and work from there.
     
  5. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Since you premix, it's an overheat alarm.

    Now you need to find out why it's going off.

    Defective sensor, water pump, t-stat. or possibly a calcium type build up in your block.

    If you can pull the t-stat, run the engine on a hose and see how it pumps the water from the opened t-stat hole. While you're looking, check that area for that build up, I mentioned.
     
  6. turkeyman

    turkeyman New Member

    Messages:
    22
    State:
    South Carolina, Swansea
    Thanks ya'll, I'll give it a shot