[usasmartindian]

Folks, had some offline discussions on this within my motorcycle group. few of hardcore bikers there told me an issue of this sort they faced on their other bikes and can be attributed to an not properly functioning O2 sensor. The sensor itself might be OK but sometimes the electrodes inside might be carbon coated based on the fact its a new bike when initially will run rich possibly coating soot on it that can over period of time can drive these sort of issues. its a simple check the voltage its giving to see if its working as intended to eliminate a faulty O2 sensor. So in the interest of checking connected using a multimeter.

2021 meteor has a 4 wired O2 sensor that is called a lamda sensor. This sensor takes in battery power to heat the sensor to certain temperature and then it kicks in as a closed loop to monitor A/F mixture controlled by ECM when engine warms up and exhaust gases heat up to check the O2 content. If the sensor reads close to 1 volt then its running rich A/F mixture causing excessive fuel consumption and if its between 0.1 to 0.4 v then its running lean mixture. Optimum A/F mixture should be within the stoichometric range mapping to anywhere between 0.5v to 0.75 v leading to optimum riding conditions for better fuel mileage. this can change based on the load on engine, speed of engine, etc. to ensure optimum fuel consumption and engine performance to keep the engine running safe all controlled by ECM based on riding conditions. So at times when its dirty or faulty the ECM will try to compensate the incorrect readings leading to bad mileage even though the sensor hasn't failed completely for the check engine light to turn on.

So having given the above detailed explanation I did this simple check and noticed the sensor is in open loop when the engine is started letting the engine warming up reading 0V. as soon as engine got warmer started seeing the voltage hovering any more from 0.87v to 0.96v. This showed it is running on rich A/F mixture. Then I let the whole thing cool down for few hours did remove the O2 sensor of the seat from exhaust pipe. noticed it was blackish around the casing. Then I used MAF sensor cleaner spray and gave it a good wash on the casing and also inside the small holes on top and sides diligently just like cleaning a MAF sensor. while flushing inside bit of carbon filled fluid came out..then wiped it clean and reinstalled in the exhaust well hand tightened so there are no leaks from there. remember one thing MAF sensor cleaning spray evaporates really quick and does remove any carbon or oily deposits..don't use any other solvents. turned on the bike with the multimeter connected and this time around it kicked in and voltage ranged from 0.45 to 0.6volts..That falls within the exact stoichometric range for A/F mixture ratio of 14.7:1 A:F ratio.

I had prior to this a full tank of gas [93 oct gas in usa] till the brim and had driven around 13 miles post fill on Trip A meter. Post all the O2 sensor cleaning the freaking bike was feeling peppy, responsive and quite smooth to ride almost like when it was behaving when it had just over 1000 miles before this whole mileage issue started. Rode for close to 36 miles and [13 already in + 36 miles more with the current at 49 miles on post full fill]. I still see the fuel gauge still all 7 bars showing tank full when in the past the first bar used to drop just after 37 miles or close to 40 miles range leading to 76mpg. I am hoping to ride more and see how this cleanup will help me further. In the past when mileage was good have noticed the first bar on the fuel gauge disappeared just around 50miles or 51 miles that would lead to an average 86-92mpg. If it does that voila have resolved the issue. Will keep this group posted when the first fuel bar disappears as its relates to 0.6 gallons per bar. thought of sharing.

[20MarkIII]

Thank you for sharing this info and your perseverance in attaining a solution. We think of our RE bikes as 'simple' but the emission standards are forcing the use of devices like the lambda sensor to make compliance. Your thread helps educate us hapless old-timers! Happy Thanksgiving!

[MMRanch]

So do I have it right that :

When the O2 sensor is hot the motor runs richer ?
and
When the O2 sensor is not hot it runs lean ?

Or

Hot particles passing past the part sticking into the exaust flow , causes a electron flow.   Like a magnet passing over a coil.    
More hot particles = more voltage.

I don't know       Perhaps I should google "how an O2 sensor works "

[Ivy]

So do I have it right that :

When the O2 sensor is hot the motor runs richer ?
and
When the O2 sensor is not hot it runs lean ?

Or

Hot particles passing past the part sticking into the exaust flow , causes a electron flow.   Like a magnet passing over a coil.    
More hot particles = more voltage.

I don't know       Perhaps I should google "how an O2 sensor works "

Yeah, i gave up at, "Optimum A/F mixture should be within the stoichometric range".

[20MarkIII]

As MMRanch mentioned, I've perused a few Youtube videos on Lambda (O2) sensors. I would very much appreciate, usasmartindian, if you would tell what method you used to hook up your voltmeter to the lambda sensor. One method I viewed was to use a piercing probe on the black wire and another method used a computer program and a fitting to the OBD port on the bike. There may be other methods.
It also seems that the O2 sensors work identically to those in autos. One mechanic stated that the sensors are usually good for over a hundred thousand miles. That's good news!
I'm wondering too if the old method of a sparkplug electrode color check would help determine if an issue existed in the first place.

[Dexter]

Folks, had some offline discussions on this within my motorcycle group. few of hardcore bikers there told me an issue of this sort they faced on their other bikes and can be attributed to an not properly functioning O2 sensor. The sensor itself might be OK but sometimes the electrodes inside might be carbon coated based on the fact its a new bike when initially will run rich possibly coating soot on it that can over period of time can drive these sort of issues. its a simple check the voltage its giving to see if its working as intended to eliminate a faulty O2 sensor. So in the interest of checking connected using a multimeter.

2021 meteor has a 4 wired O2 sensor that is called a lamda sensor. This sensor takes in battery power to heat the sensor to certain temperature and then it kicks in as a closed loop to monitor A/F mixture controlled by ECM when engine warms up and exhaust gases heat up to check the O2 content. If the sensor reads close to 1 volt then its running rich A/F mixture causing excessive fuel consumption and if its between 0.1 to 0.4 v then its running lean mixture. Optimum A/F mixture should be within the stoichometric range mapping to anywhere between 0.5v to 0.75 v leading to optimum riding conditions for better fuel mileage. this can change based on the load on engine, speed of engine, etc. to ensure optimum fuel consumption and engine performance to keep the engine running safe all controlled by ECM based on riding conditions. So at times when its dirty or faulty the ECM will try to compensate the incorrect readings leading to bad mileage even though the sensor hasn't failed completely for the check engine light to turn on.

So having given the above detailed explanation I did this simple check and noticed the sensor is in open loop when the engine is started letting the engine warming up reading 0V. as soon as engine got warmer started seeing the voltage hovering any more from 0.87v to 0.96v. This showed it is running on rich A/F mixture. Then I let the whole thing cool down for few hours did remove the O2 sensor of the seat from exhaust pipe. noticed it was blackish around the casing. Then I used MAF sensor cleaner spray and gave it a good wash on the casing and also inside the small holes on top and sides diligently just like cleaning a MAF sensor. while flushing inside bit of carbon filled fluid came out..then wiped it clean and reinstalled in the exhaust well hand tightened so there are no leaks from there. remember one thing MAF sensor cleaning spray evaporates really quick and does remove any carbon or oily deposits..don't use any other solvents. turned on the bike with the multimeter connected and this time around it kicked in and voltage ranged from 0.45 to 0.6volts..That falls within the exact stoichometric range for A/F mixture ratio of 14.7:1 A:F ratio.

I had prior to this a full tank of gas [93 oct gas in usa] till the brim and had driven around 13 miles post fill on Trip A meter. Post all the O2 sensor cleaning the freaking bike was feeling peppy, responsive and quite smooth to ride almost like when it was behaving when it had just over 1000 miles before this whole mileage issue started. Rode for close to 36 miles and [13 already in + 36 miles more with the current at 49 miles on post full fill]. I still see the fuel gauge still all 7 bars showing tank full when in the past the first bar used to drop just after 37 miles or close to 40 miles range leading to 76mpg. I am hoping to ride more and see how this cleanup will help me further. In the past when mileage was good have noticed the first bar on the fuel gauge disappeared just around 50miles or 51 miles that would lead to an average 86-92mpg. If it does that voila have resolved the issue. Will keep this group posted when the first fuel bar disappears as its relates to 0.6 gallons per bar. thought of sharing.

While I'm hoping this little "exercise" in obsessing over varying mpg figures is now resolved to the OP's satisfaction, I'm also reminded of this classic case of gobbledygook from years ago.

https://www.youtube.com/watch?v=Ac7G7xOG2Ag

[Dexter]

OK, I had to come back here one more time to see if I could digest this O2 fault scenario that the OP thinks he has discovered. It wasn't until I got to the last paragraph that I realized that his methodology for computing the actual fuel mileage was quite bizarre.

Mr. usasmartindian is basing his figures on how soon the fuel bars on his instrument cluster disappear, which we have all ascertained, after having these Meteors for a while, gives us a totally inaccurate way to tell how much fuel is actually in the tank! Especially when you get to the last bar or two. We have all seen those bars come and go, like a kid playing with a light switch, which I can only assume is because of the sloshing of the fuel in the tank and also the angle of the terrain that you may be travelling over.

The fuel gauge certainly is one of the Meteor's big shortcomings, for those that like to run their tanks down before a refill. Even the low fuel light plays up, going on and off for dozens of miles after it first appears. Totally unreliable.

The solution to the OP's problem now seems pretty obvious to me. There is nothing wrong with the bike, just his method of computing his fuel consumption. 

The proper way to determine fuel mileage would be to fill the tank (only to the splash guard - NOT the brim), record the bike's mileage and then ride until the tank is fairly low again, at which point you note the mileage again and record how much fuel went into the tank to bring it back to the splash guard. Then do the math.

EDIT:

I would add that his estimate of 0.6 gallons per bar is incorrect, for the tank holds, according to the manual, approximately 15 litres, which equates to 3.99 US gallons, for a bar ratio breakdown of .57 gallons per bar. Of course, the shape of the fuel tank determines how fast those bars disappear as well and there is also the dead stock, unusable in the tank, to be considered.

[MMRanch]

Well , here's the heart of what I found .     The results of keeping it clean might be a "Hotter" running O2 (which is good) .    So cleaning it every oil change could save fuel ?   Also - turning on the switch for a 30 second delay in starting might save on the fuel bill too (long enough to put my gloves on ) ??

The Upstream Oxygen Sensor (Oxygen Sensor 1)
Oxygen sensor 1 is the upstream oxygen sensor in relation to the catalytic converter. It measures the air-fuel ratio of the exhaust coming out of the exhaust manifold and sends the high and low voltage signals to the powertrain control module in order to regulate the air-fuel mixture. When the powertrain control module receives a low voltage (lean) signal, it compensates by increasing the amount of fuel in the mixture. When the powertrain control module receives a high voltage (rich) signal, it leans the mixture by reducing the amount of fuel it adds to the mixture.

The powertrain control module’s use of the input from the oxygen sensor to regulate the fuel mixture is known as a closed feedback control loop. This closed loop operation results in a constant flip-flop between rich and lean, which allows the catalytic converter to minimize emissions by keeping the overall average ratio of the fuel mixture in proper balance.

However, when a cold engine is started, or if an oxygen sensor fails, the powertrain control module enters into open loop operation. In open loop operation, the powertrain control module does not receive a signal from the oxygen sensor and orders a fixed rich fuel mixture. Open loop operation results in increased fuel consumptions and emissions. Many newer oxygen sensors contain heating elements to help them get to operating temperature quickly in order to minimize the amount of time spent in open loop operation.

The Downstream Oxygen Sensor (Oxygen Sensor 2)
Oxygen sensor 2 is the downstream oxygen sensor in relationship to the catalytic converter. It measures the air-fuel ratio coming out of the catalytic converter to ensure the catalytic converter is functioning properly. The catalytic converter works to maintain the stoichiometric air-fuel ratio 14.7:1 while the powertrain control module constantly flip-flops between rich and lean air-fuel mixtures due to the input from the upstream oxygen sensor (sensor 1). Therefore, the downstream oxygen sensor (sensor 2) should produce a steady voltage of approximately 0.45 volts.
 

Hay !  We all "Live and Learn" , !!   

[Ivy]

I get that a bad O2 sensor can cause fueling issues, but why is the MIL light not on and in my experience a bad O2 sensor causes rough running, misfires, hesitation, etc.
I find it hard to except a bit of carbon build up would make any difference, unless it was sooted up really bad, which is unlikely give the age of the bike.

One way to test a bad O2 sensor is to run with it disconnected and see what the difference is.

[ptclassic]

Probably as soon as it is disconnected you get engine light on

The only way to be sure is to do the math.. fill the tank, drive, and fill again

Like already been said

[Ivy]

Probably as soon as it is disconnected you get engine light on

The only way to be sure is to do the math.. fill the tank, drive, and fill again

Like already been said

Yes, that will tell you your consumption has increased or not but not why.

[MMRanch]

My fuel consumption has increased with the cooler weather ... its down to the high 70's mpg(US),
 .......

Those lazy summer days of putt-putting around on the back roads and getting 90mpg have give way to running 65 in the 55 zones to get to where I'm going.

[longstrokeclassic]

I use Fuelly.com to keep an accurate track on my mpg.
There’s a couple of Meteors on there already👍

[MMRanch]

Hay usasmartindian

I've had a "Warped Disk" feeling coming out of the front end for a while now.    Not only feeling it at low speed but :
with the bike on the center stand and the front wheel off the ground the brake drags a lot in one spot.
I have measured the disk all the way around and found it to uniform. 
I have clamped my "Dial-Caliber" on the bottom of the fork and mesured the amount of RUN-OUT (.005-.006").
I have removed the Caliper and lubed the piston and slide area's.
Changed the Brake fluid to "Known" Dot 4" fluid.
Still there is a "DRAG" IN ONE AREA ?   Its like the Master Cylinder is not turning loose all the way.
My point is :  That drag is not conductive to the best MPG.
Do you have a similar issue ? 

[gizzo]

While I'm hoping this little "exercise" in obsessing over varying mpg figures is now resolved to the OP's satisfaction, I'm also reminded of this classic case of gobbledygook from years ago.

https://www.youtube.com/watch?v=Ac7G7xOG2Ag

He's doing the best he can in his second language. How's your Hindi?