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I bet I could bypass any unit. I've void warranty LOL . most likely 1 of 2 ways the sensor works, 1) like a switch when set to alarm it opens or closes a circuit. easy to bypass. , 2) harder but not by much it has a resistance value , like X-ohms when alarming or X-ohms when not. just need to find this value and use a restitor to simulate .
 

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I bet I could bypass any unit. I've void warranty LOL . most likely 1 of 2 ways the sensor works, 1) like a switch when set to alarm it opens or closes a circuit. easy to bypass. , 2) harder but not by much it has a resistance value , like X-ohms when alarming or X-ohms when not. just need to find this value and use a restitor to simulate .

The 2nd method you describe is not how a CO sensor works. Unfortunately is far more complicated than a resistance plot. It works on a difference of voltage in the control circuit that runs it. Subbing in a simple resistor wont bypass it. The control circuit can operate as a simple on/off switch based on the sensors output such as killing the ignition spark on the kill wire terminal. That control circuit may be far more complex such as outputting a pulse signal to the inverter module, to which that module translates as an on/off state for the inverter output and kills the ignition. Without that pulse signal, the inverter will shut down the generator after a few seconds. Sadly these sensors are far from simple in many cases.

Take this sensor for example: https://www.digikey.com/en/products/detail/spec-sensors-llc/110-102/6136363

All CO sensors have a shelf and service life. That is all determined by RH and temperature. It also responds differently too based on those specs. So how you store your generator, if the RH/Temp is frequently high, it shortens the life expectancy.

Typically they are rated for 10 years of service life, but at ideal environmental conditions. More realistically in practice, these sensors will see about 5-7years before failing. My technician contact at Firman told me that the control circuit design they had on their sensors were too oversensitive, so a "bad" batch made the sensors problematic. They have since corrected it, and if you do have a faulty sensor, it is easily replaced without digging into the wiring/voiding warranty.

The circuit design in general is intriguing to me, but I can see how complexity causes diagnostic difficulty. As someone else posted, Sensors cannot fix stupid!
 

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The 2nd method you describe is not how a CO sensor works. Unfortunately is far more complicated than a resistance plot. It works on a difference of voltage in the control circuit that runs it. Subbing in a simple resistor wont bypass it. The control circuit can operate as a simple on/off switch based on the sensors output such as killing the ignition spark on the kill wire terminal. That control circuit may be far more complex such as outputting a pulse signal to the inverter module, to which that module translates as an on/off state for the inverter output and kills the ignition. Without that pulse signal, the inverter will shut down the generator after a few seconds. Sadly these sensors are far from simple in many cases.

Take this sensor for example: https://www.digikey.com/en/products/detail/spec-sensors-llc/110-102/6136363

All CO sensors have a shelf and service life. That is all determined by RH and temperature. It also responds differently too based on those specs. So how you store your generator, if the RH/Temp is frequently high, it shortens the life expectancy.

Typically they are rated for 10 years of service life, but at ideal environmental conditions. More realistically in practice, these sensors will see about 5-7years before failing. My technician contact at Firman told me that the control circuit design they had on their sensors were too oversensitive, so a "bad" batch made the sensors problematic. They have since corrected it, and if you do have a faulty sensor, it is easily replaced without digging into the wiring/voiding warranty.

The circuit design in general is intriguing to me, but I can see how complexity causes diagnostic difficulty. As someone else posted, Sensors cannot fix stupid!
I still think I could bypass it, I really don't think that the Chinese generators are going to spend much money on anything so complex .( maybe honda EFI model ) Not that its impossible to do so. Just all about $$ . Also my warranty is only 90 days on the predator 9500 from the store unless you but a 2 year warranty for 500 plus $ ... and they don't offer anything higher so the 5 to 7 years you are saying is likely . you will be way out of warranty . and truth be told the generator itself will be out of life at this point. from my experiacne you start have many other issues before then , I.E. replacing the carb , etc leaking or burning oil badly
 

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There are YT videos on how to bypass the CO sensor on the Predator 9500... The guy below just unhooked a hardness going to the sensor module. But in addition to that, he also cut a 2nd set of wires but then bridged the two wires together on the engine side to fool it to keep running.

So it appears that in this setup, the CO sensor is configured for normally-closed (NC) and will switch open when it detects CO to kill the engine.


This is crucial info if you're in a bind due to a faulty sensor preventing the engine from starting. It's really up to you if you want to disable it now or after it has failed.
 

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There are YT videos on how to bypass the CO sensor on the Predator 9500... The guy below just unhooked a hardness going to the sensor module. But in addition to that, he also cut a 2nd set of wires but then bridged the two wires together on the engine side to fool it to keep running.

So it appears that in this setup, the CO sensor is configured for normally-closed (NC) and will switch open when it detects CO to kill the engine.


This is crucial info if you're in a bind due to a faulty sensor preventing the engine from starting. It's really up to you if you want to disable it now or after it has failed.
so like I said in my post ... its typically like a switch that is either normally open or closed. and could be bypassed. and yes it could be done more complexly but is not normally the case because that cost money and they always want the cheap way out.
 

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The 2nd method you describe is not how a CO sensor works. Unfortunately is far more complicated than a resistance plot. It works on a difference of voltage in the control circuit that runs it. Subbing in a simple resistor wont bypass it. The control circuit can operate as a simple on/off switch based on the sensors output such as killing the ignition spark on the kill wire terminal. That control circuit may be far more complex such as outputting a pulse signal to the inverter module, to which that module translates as an on/off state for the inverter output and kills the ignition. Without that pulse signal, the inverter will shut down the generator after a few seconds. Sadly these sensors are far from simple in many cases.

Take this sensor for example: https://www.digikey.com/en/products/detail/spec-sensors-llc/110-102/6136363

All CO sensors have a shelf and service life. That is all determined by RH and temperature. It also responds differently too based on those specs. So how you store your generator, if the RH/Temp is frequently high, it shortens the life expectancy.

Typically they are rated for 10 years of service life, but at ideal environmental conditions. More realistically in practice, these sensors will see about 5-7years before failing. My technician contact at Firman told me that the control circuit design they had on their sensors were too oversensitive, so a "bad" batch made the sensors problematic. They have since corrected it, and if you do have a faulty sensor, it is easily replaced without digging into the wiring/voiding warranty.

The circuit design in general is intriguing to me, but I can see how complexity causes diagnostic difficulty. As someone else posted, Sensors cannot fix stupid!
it appears NOT , see
OrlyP post below . its a simple bypass switch...........like I said first LOL
 

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To be fair, I agree with bassguitarist that it is design-specific. HF or their OEMs could anytime change their CO sensor design to account for parts availability. There are no standards afaik on how a sensor should shutdown the engine. It just needs to happen.
 

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that was more of a joke
lol

In my defense, sarcasm doesn't always get across clearly over written mediums. But I'd be sure to take my sarcasm pills from now on. ;)

Anyway, that's the gist of it. For better or for worse, remove/disable the built-in CO detector at your own risk.

When the time comes and you're planning on selling or loaning the generator to someone else, you should either put it back together OR expressly inform the other party whether or not the CO detector is working or not.
 
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