another "overheat buzzer" question

waterwhiz

Cadet
Joined
Apr 7, 2009
Messages
8
Been a while since I last posted but here goes. 1996 120 hp Force by Mercury on a 17/2 Fischer. Impeller changed every year and water pump inspected. Had been running the stock thermostat and also have always changed it yearly. Fresh (maybe brackish) river water only. Was advised by me Mercury mecahic to run a hollow stat. No problems with the exception of water pressure reading went from 15/17 psi wot to about 9 amd idle(800) about 3 lbs. but expected this change. Had this problem even before the hollow stat change i.a. at wot for about 2 min. the buzzer(or alarm) goes off till I power down to idle. Measured temperature with thermometer at the "pee hole" it it never reads higher than 125 degrees and I can rest my forearm on the block with no problem. I believe it's in the sensor, the only one I see held into the block with a spring clipI would either like to check, replace, (which I haven't been able to locate,HELP) or possibly connect a workable auto style temp gauge. My water pressure gauge is connected on the very top of the block and can't see any additional location for a temp gauge. Any help, instruction or advice would be greatly appreciated.

thanks
waterwhiz
 

fucawi

Banned
Joined
May 18, 2011
Messages
1,039
Re: another "overheat buzzer" question

Take out your over temp switch and rig up a battery and bulb to its contact ( a tag and earth treads) and stick it in the electric kettle with a thermometer ...turn on kettle ..stir water and see what temp the light comes on ..( or use an ohm meter) ...Temp gauges usually 1/8 NPT which is nearer to 10 mm but tapered
 
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