My 1999 T50TLRX sounds a steady alarm I cannot determine. It has only 250 hrs on it. The alarm typically sounds at low speeds, sometimes as soon as pull from the dock with a cool engine, sometimes later when I slow to 'no wake', and sometimes not at all (though lately it's been going off more). The water impeller was replaced last summer and water flow is good and barely warm. My local Yamaha dealer-mechanic seems lost. I'm thinking it's a bad thermo sensor, not an oil sensor. There is one sensor mounted on the surface of the block at the top on port side, and another at lower rear of the block. The two look the same (nickel-size and black.... the rear one has 2 blue wires.... not sure about the other). Any advice on how to isoate/fix the problem would really be appreciated. Thanks.
