1998 Force 90HP Overheat Alarm

[Oldsaltydog]

I have just purchased the boat and motor and it runs well, but I would like to know more about the water temperature overheat alarm. The seller lost the original manual and a promised manual from Bayliner is still "in the mail". <br /><br />How does the warning sytem work? Does the temperature sensor send a signal to the boat horn when the temperature gets too high? Are all motors of my kind and vintage equipped with this device? How can I test the alarm?<br /><br />If you could help me out, I would really appreciate it.

 

[seldont]

Re: 1998 Force 90HP Overheat Alarm

I cannot answer if all motors were equipped with one but most at least since the late 80s were I think. Your 90 horse should be equipped with one. Looking at your motor from the rear there is a small round sensor on the top left of the head with only one wire coming from it I believe. Follow the wire from the sensor back to where it makes a connection via a plug in type bullet connector. Unplug it there and with your switch in the on position run a wire from a good ground on the motor to the female end of the wire you unplugged (the part that follows the wiring harness towrd the controls on you boat) and the warning horn should sound. This way you know the wiring from the motor to the horn is good and the horn is working properly. I just tested mine a couple of nights ago. I think it is recommended to do at least once a year.

 

[Brooksyde]

Re: 1998 Force 90HP Overheat Alarm

I have just tested the sensor on my force 120. If you look in the forum under "booksyde" you will see the problem that I had. If you disconnect the sensor from the wiring block it can be removed from the engine be taking out the curclip and gently pulling it. You will need a thermometer and a multimeter. Immerse the sensor in hot water and test for a current. Keep adding boiling water until you get a circuit. It is at this temperature that the horn will sound. If you now add cold water until you loose the ciruit this will tell you the temperature at which the horn shuts down. Best of luck.