F150 Higher Idle 1100-1200 rpm

[boscoe99]

Please tell us about fail safe mode in relation to the thermoswitch as shown in the above attachment.

I am not sure what you are asking about. Recognizing that the comment is for rodnut of course. Waiting to hear what he has to say.

There is no fail safe mode with respect to a thermoswitch. The switch simply tells the CDI/ECU that it has closed, indicating the motor is hot. The CDI/ECU will put the motor into RPM reduction mode and sound the alarm. It will also flash or illuminate lights if the boat is so equipped. It is up to the operator then to protect the motor. By shutting it down immediately. If not sooner. If the operator fails to act the motor will continue to operate until it may be severely damaged. It won't be safe. It won't be pretty.

Yamaha's use of the term "fail safe" is very poor. Maybe something is lost in the translation from Jap to English. In the case of a thermoswitch closing, fail safe to me when mean that the engine would shut itself down. And not rely on the operator to do so. Many operators don't. At their own peril.

[cousinabe]

I got the winky blinky to work. Blue butt was plugged into wrong female. Found the blue/white wire tucked way under. User error.

Flashing 1.

[pstephens46]

I am not sure what you are asking about. Recognizing that the comment is for rodnut of course. Waiting to hear what he has to say.

There is no fail safe mode with respect to a thermoswitch. The switch simply tells the CDI/ECU that it has closed, indicating the motor is hot. The CDI/ECU will put the motor into RPM reduction mode and sound the alarm. It will also flash or illuminate lights if the boat is so equipped. It is up to the operator then to protect the motor. By shutting it down immediately. If not sooner. If the operator fails to act the motor will continue to operate until it may be severely damaged. It won't be safe. It won't be pretty.

Yamaha's use of the term "fail safe" is very poor. Maybe something is lost in the translation from Jap to English. In the case of a thermoswitch closing, fail safe to me when mean that the engine would shut itself down. And not rely on the operator to do so. Many operators don't. At their own peril.

That fail safe document is confusing. Take a look at the details next to thermo switch in the second column. Switch on below certain temp or off above 266?

[boscoe99]

That fail safe document is confusing. Take a look at the details next to thermoswitch in the second column. Switch on below certain temp or off above 266?

It can be confusing.

What is being said is

(a) if the thermoswitch is closed (due to excessive head temperature) but the engine temperature (cylinder block based on thermosensor) is 104* F or less there will be normal control and

(b) if the engine temperature (cylinder block based on thermosensor) is above 266* F but the thermoswitch is open there will be normal engine control.

The ECU is looking at data from both the thermoswitch and the thermosensor at the same time, comparing what one is reporting with what the other is reporting, to make a decision as to what to do.

Another confusion point IMO. The thermoswitch is listed under the column headed "malfunctioning item". I don't think that a thermoswitch that is closed because of over temperature is malfunctioning. It is doing just what it is supposed to do. Again, might be the result of translation between Jap and Eng.

[pstephens46]

Understand now.....thanks.

[cousinabe]

Solved.
WB flashing 1.
Tps read .75.
Recalibrated throttle valves. Set tps to .66.
tightened throttle stop screw till tps output .70.

Idling at 750.

[rodbolt17]

that is what is called an in range failure.
the ECU saw the extra .o5V and increased the ign timing and ISC and injector on time for the MAP and YPS. it did exactly what it was supposed to do. you could have found it with a timing light. you would have noticed about 10* BTDC.
the only two you can disconnect and not have the ecu toss a code is the ISC and the thermoswitch's.

[cousinabe]

that is what is called an in range failure.
the ECU saw the extra .o5V and increased the ign timing and ISC and injector on time for the MAP and YPS. it did exactly what it was supposed to do. you could have found it with a timing light. you would have noticed about 10* BTDC.
the only two you can disconnect and not have the ecu toss a code is the ISC and the thermoswitch's.

Thanks, I'm trying to figure out who messed with the throttle stop screw?!
Worked fine lat season when loading on trailer before storing in boat yard for the winter...