2003 F90TLRB Temp sensor

[entglass51]

I think I posted a question as a reply, my bad
My question is How to test the Temp sensor function, the circuit works 220 ohm jumper on black yellow/ black wires, buzzer sounds
Testing sensor? place in hot water check ohms?

Thanks, Gene

[boscoe99]

The service manual describes the test for the sensor.

The sensor is placed in hot water and its resistance is measured as a function of temperature, at varying temperatures.

To test the system the sensor is disconnected from the engine harness. On the engine side connector a 220 ohm resistor is jumpered between the two terminals in the connector. Start the motor and let it idle. After about a minute or so time the alarm should sound.

[entglass51]

Thank you I'll be testing that with some hot water

I did test system with 220 ohm resistor buzzer worked

Now you want to hear a weird one! Boat runs great 5-6 miles hit boat wake boat idles down or goes to limp mode, sit for while at idle, gets right back on plane runs great but happens some times
Did fuel pump diaphram, Thermostat,fuel filter, fresh non ethanol, all fuel lines
everything fuel related, because it seemed fuel related
yesterday running on hose, shook the boat, shook the motor purred like a kitten
touched the coil power wire move it toward block engine races up then starts to stumble let wire go it fixes it's self, move wire again same results
Coils where tested by certified yamaha service center one was replaced just not this one
Fingers crossed after replacement everything runs as intended

[boscoe99]

To get into the RPM reduction model (limp as you call it) the motor has to be in an over temperature condition or low oil pressure condition. Either of which will cause the buzzer to sound and certain lights/symbols to appear on a Yamaha tachometer

If you are not hearing the buzzer I don't think the motor is in RPM reduction mode. Could simply be a fuel starvation issue or perhaps a faulty wire/component issue.

When you refer to the coil power wire are you talking about the input lead or the output lead?