Mariner 175 Buzz

nigelk · 21-08-2005, 10:28 PM

Been out in my friends new acquisition.

He's got an old (circa 1985) Mariner 175. Plenty of water through the tell tale, but after a while the warning buzzer comes on.

After switching off then restarting a short while later, all is well ..... until the next time.

Any ideas ??? (Apart from disconnecting the buzzer!)

Thanks.

Captain Chaos · 21-08-2005, 10:31 PM

what kind of buzz?

continuous meens overheat,
intermitent is stuff like low oil in reservior etc

nigelk · 21-08-2005, 10:39 PM

Continuous buzz !!

But there was plenty of water ?? Could it still be overheating ?

No Oil reservoir - pre - mix, so not oil.

TheMutzNuts · 21-08-2005, 11:24 PM

water in the fuel filter?unscrew it an check.

Captain Chaos · 21-08-2005, 11:40 PM

dont think an 85 motor would have sensor there.

JamesM · 22-08-2005, 12:13 AM

If your sure its not over heating then it could be that the over heat sender switch in the head is breaking down.

All that happens is a +ve feed is taken from the loom to one side of the buzzer, the other side of the buzzer goes to the switch in the head. When it reaches a certain temperature the switch completes the circuit by earthing the buzzer wire to the engine earth and thus the buzzer sounds. It maybe that his is occuring at a lower temp due to the switch breaking down internally. What could also be happening is that the insulation on the wire that goes to the switch may have worn through and thus the internal cores or the wire may be intermitantly coming into contact with a metal part of the engine, which will of course be an earth.

Check the wiring for damage and if you dont find anything buy a new over heat sender switch.

TheMutzNuts · 22-08-2005, 12:14 AM

Quote:

Originally posted by Captain Chaos
dont think an 85 motor would have sensor there.

Hmmm, I think mabey you could be right

BluFin · 22-08-2005, 08:27 AM

Don't forget it may be a faulty o'heat sensor, they are pretty reliable though. It is possible to get an o'heat with water flow and a reduced pressure I did it once but was so bloody high nobody would ever go those heights normally. Might be worth having a look at the divider plate if the motor is off on performance.
You can test the sensor by connecting it to a multimeter and measure the Continuity by poping it in a kettle with a thermometer, see when it all happpens and at what temperature.