Thx for your reply ClassicAQ. I have some new info on its behavior.
With the engine cover off and one thermo switch disconnected I ran WOT again. Same thing after a few minutes, partial shut down. I reached back and unplugged the other thermo switch and engine immediately jumped back to full power. Had an Hurray moment then suspecting one or both switches.
Still confused though. I'd also placed each switch in a pot of water on the stove with ohm meter attached. Each went from open to closed at your mentioned temp 180-185. ???
Not sure if my other alarm system even works. I'm at least the third owner. Have never heard an alarm. Didn't know about the red light on the tach. Thanks for that info. Oh and you used the term "stats". I'm not familiar with that.
Disregard my use of the word "stats", as I was meaning to type sensors. I've attached a copy of the thermosensor test procedure. There will be no continuity (closed circuit) through sensor until the temp reaches 180-185º, at which point the circuit opens and is continuous.
Re: Disconnecting sensors from engine while running
If you got the alarm while running with only one sensor, did you also disconnect this sensor and replace the former disconnected sensor, then run engine again? From what I take, you disconnected one sensor, ran engine, got the alarm, then disconnected the lone sensor (no sensors installed), ran engine, did not get the alarm. Is this correct?
Because if so, all you did was completely disable the high temp alarm system. By pulling out both sensors the engine has no way to communicate with the alarm system. So essentially, if you kept both sensors disconnected and continued to run the engine as it overheats....only a matter of time, rather seconds, before disaster. With all of this said, if you can get your hands on an external temp laser you'll know for sure if you've got an electrical alarm issue or over heat issue.
Your low oil alarm is separate from high temp alarm. Two different circuits involved.
Below is the procedure to test your high temp and low oil alarm systems:
To test the over temperature system on 99% of all Yams simply disconnect the pink wire and the black wire connected to the thermoswitch. Then connect the black wire to the pink wire on the engine side harness and start the motor. Wait up to a minute or so. You should hear the horn. If you have certain Yamaha tachometers (or maybe lights on the motor or on the dash) the lights will illuminate or an icon will flash. So, with the horn you know there is a problem. With the light or icon you will know what the problem is related to.
To test the low oil quantity system in an oil injected two stroke simply drain the oil from the main engine mounted tank. Start the motor. The horn will be sounding indicating there is a problem. If you have certain Yamaha tachometers (or maybe lights on the motor or on the dash) the lights will illuminate or an icon will flash. So, with the horn you know there is a problem. With the light or icon you will know what the problem is related to. Refill the oil tank.
