[takidd4597]

I have an overheat alarm going off but have great tell-tale flow. I can keep my hand in the stream forever.I have a small nut with a wire next t o the 1st spark plug on the top can anyone tell me if this is what it is: 87- 96829A 1 TEMPERATURE SWITCH ASSEMBLY (260 DEGREES) 1 $69.20 Also do these go bad or what can I do to fix it or what?It is on a 1988 marinew 60hp motor. Mercury parts express has a different part for the cylinder head that is:38 12415 TEMPERATURE SENDER (POWERBOAT) 1 $15.50 39 84- 88824A 7 CABLE ASSEMBLY (POWERBOAT) 1 $22.30 I don't seem to have one of these on mine and have a feeling that it goes lower on the head where I have a plug(bolt). How would this work and what else woulds I need for this instead of the switch. Web page etc would help also what temp should I be at?

[rickdb1boat]

takidd4597You are talking about 2 different things. What you need is the temperture Sensor(Temp. Switch Assem.) which sounds the alarm when the engine is overheating. The other part that you refer to are temperture sending units, which would be used with a remote gauge to moniter your temp. The sensors do fail on those motors causing a false alarm. When the alarm sounds, disconnect the wire from the sensor and see if it stops. Your motor should run about 140 degrees. You can check this with a thermomelt stick available at the dealer, which determines the temp. of the cylinder head, to check if you are indeed overheating or if the switch is causing the problem. If the alarm goes off before the mark you made with the stick melts, then you have a faulty switch.