Temp Alarm for Merc 200hp

Discussion in 'Bubba's Outboards' started by mullyden, Sep 18, 2006.

  1. mullyden

    mullyden New Member

    Messages:
    573
    State:
    Baton Rouge , L
    BobPaul and Bubba,
    My Merc gets high temp alarm on many trips onto the Mississippi River. I can go 2-3 miles at about 4000 rpm and the continuous alarm goes off. I throttle down to an idle and it clears up after a short period. The telltale pees pretty strong at idle and blasts out with higher throttle settings. The first couple of times it happened I assumed I got silt into cooling system and used the hose connection at the back of the motor and flushed it. The next time (until recently) never overtemped. Now, even after the hose out, I will normally get the alarm. Yesterday, I went out @ 4000 and got alarm. It cleared after idling and we fished. On the way back I went a little faster ~5000 and got no alarm. I had impeller replaced last year but the river at times is somewhat silty. The shop removed the thermostats at the same time. What do you think? Impeller, sensor, either, other mechanical problem possibilities? Thanks.
     
  2. duxsrus

    duxsrus New Member

    Messages:
    1,014
    State:
    SW Ohio
    This might sound dumb, but you sure it isn't the oil alarm. My buddies motor is doing the same thing but it starts that nonsense right after starting up. It doesn't seem that it could be overheating that fast.
     

  3. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Hi Denny, nice to hear from you. Too bad it's because you've got a problem. Tell Mary I said HI! I hope your both doing well. I sure miss those La gatherings. I Don't know if I'll ever get back there, but it sure was some good memories.

    You should definately get the whole water pump changed out, not just the impellor, because of the water you run in.

    It could also be a faulty sensor, but don't take any chances.

    I'd pull the thermostat covers and give it a good flushing just to check for a silt build up.

    You should really get your water pump done yearly.
     
  4. mullyden

    mullyden New Member

    Messages:
    573
    State:
    Baton Rouge , L
    I get intermittent alarm for oil level problem, and that seems to be working fine. Looks like I'm gonna have to part with a few $ and get a new pump. Bobpaul, had a great trip Sunday. If you get and chance take a peak at LA Baton Rouge area Miss fishing for a couple of picks. In about 4 hr Mary (she says Hi to to you), my daughter and her boyfriend caught 181 lb of fish, 38 total nice ones. We released the largest one.~ 12 lb. Take care and thanks for the info.
     
  5. mullyden

    mullyden New Member

    Messages:
    573
    State:
    Baton Rouge , L
    Bobpaul,
    You hit it on the head. The water pump had several problems. Impeller was swelled and distorted (replaced not too long ago, but mechanic said they are seeing more of them lately) but probably more importantly, several pieces of the gaskets around the pump were missing. They theorized that it was sucking in some air which obviously doesn't remove heat as well as water. They replaced the entire pump as you suggested and say it otherwise is aok. I really think I need to take it out and check it.....hey Mary, I need to check out the motor, see ya later. Seriously, I am anxious to get back out. Again, thanks again for your accurate advice.
     
  6. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Denny, helping you out is a pleasure. You get out there and check things out to be sure it's ok. Mary will understand.

    I'd sure like to get back to La and get with you folks, round up April and Doug, get Randall and Tabatha and talk those folks from Sante Fe Tx to swing by and have us a ball.

    Right now I'm wishful thinking, but it ain't out of the realm of possabillities yet.