1996 gti overtemp buzzer

[steevis74]

I got a 1996 gti 720 rotax and idling throught the no wake zone all is good I get on the throttle and up to plane and the temp light and buzzer goes off. I know its not too hot cause I stopped to check it and the motor is only warm to the touch but not hot. I took the sensor out of the top of the head when I got home and with it plugged in and not touching anything it is good but when you touch it to any metal it goes off again. Is this a bad sensor or should I look for another explantion. I checked to make sure the water was going through the head and wasnt blocked. Also the water inlet seems high on the hull to me ontop of the jet pump. I assume it is factory like this but it seems like that part of the ski isnt in the water enough to suck it up and does the exhaust create the vacuum to get the water to the motor? Thanks in advance!!

 

[CodyT]

It would seem as if you've got a short. Possibly in the sensor itself or in the wiring. The sensor measures temperature with resistance. A short to the head cover would cause the resistance to drop out and sound the buzzer. I suppose that there is something with the MPEM that should be checked as well but I'm not sure.

You can go though the trouble of Ohming out the wiring and sensor or do as I did. Remove the stock sensor and fit the socket with a sensor going to a analog or digital gauge, monitor the engine temps yourself. With a live view of your engine temps you're more likely to notice a loss of coolant before the buzzer would have sounded.

I've also wired a flow sensor into the oil line which goes to a flashing red LED. If the pump stops I'll know before engine damage can occur.

CodyT