One exhaust pipe getting visibly red

[elykyle15]

For those still here..

Interestingly, after someone brought up "sensors", I thought to disconnect my oxygen sensor on the exhaust to see if anything changed. I noticed that the oxygen sensor, although it appeared to be connected, it wasn't fully clipped in. I fully unplugged it and expected a check engine light, but there wasn't. I then proceeded to drive around to recheck avg. MPG; no difference. I reconnected, and fully clipped in, the sensor and rode around again; only a small increase up to ~39MPG. 

Amicrazy, or should have the check engine light came on with the sensor unplugged?

[M. Hausknecht]

Yes, very interesting.  I don't have an OEM ecu or narrowband O2 sensor so I don't know what specific problems trigger the check engine light. Perhaps someone else here knows. Putting that aside, it is easy to understand that the ecu would call for more fuel in the absence of a signal from the O2 sensor; that would be the safest course of action for the motor under the circumstances. 

With the sensor now connected, do you notice any differences in how the bike operates?

 

 

[wollerms]

Just FYI, my 2019 MT07 has a full AKRA exhaust and a 2WDW flash, according to 2WDW the O2 sensor should still be plugged in on this bike. I get 50-55 mpg ripping on it in the mountains. 

My 2017 SV650 has a full M4 exhaust and a 2WDW flash but they suggest on this bike to disconnect the O2 sensor. I did and did not get a check engine light or anything. 

Edited April 9, 2022 by wollerms
spelling

[AP996]

Just now, elykyle15 said:

For those still here..

Interestingly, after someone brought up "sensors", I thought to disconnect my oxygen sensor on the exhaust to see if anything changed. I noticed that the oxygen sensor, although it appeared to be connected, it wasn't fully clipped in. I fully unplugged it and expected a check engine light, but there wasn't. I then proceeded to drive around to recheck avg. MPG; no difference. I reconnected, and fully clipped in, the sensor and rode around again; only a small increase up to ~39MPG. 

Amicrazy, or should have the check engine light came on with the sensor unplugged?

I have my stock o2 sensor disconnected and it doesn’t bring any check engine light on so I think yours is normal in that respect.

[elykyle15]

Just now, M. Hausknecht said:

With the sensor now connected, do you notice any differences in how the bike operates?

Truthfully, not that I could tell other than the AVG MPG improved slightly.

[elykyle15]

Just now, AP996 said:

I have my stock o2 sensor disconnected and it doesn’t bring any check engine light on so I think yours is normal in that respect.

Thanks for confirming.

Curious, did you notice any change in AVG MPG?

[AP996]

Just now, elykyle15 said:

Thanks for confirming.

Curious, did you notice any change in AVG MPG?

Sorry I couldn’t really say, multiple other mods and don’t really take any notice of fuel consumption, however I definitely don’t have any problem with poor running and red exhaust pipes.

[sweetscience]

Yeah, my bike's right side exhaust pipe ( cylinder 2) seems to have a darker discoloration than the left side.  That side is running hotter for sure.  Since this is a by product of the limited tuning and CP2 engine characteristics, I am not terribly worried about it. 

Talking outta my a$$ here, because the CP2 has an uneven firing order, perhaps an ideal tune would require lambda sensors for each cylinder exhaust ports.  Instead of only using one O2 sensor to get the average for both.  But this is my speculation and could be false. 

Be that as it may, I had the ECU flashed to get a smoother, cooler running engine.  It will be interesting to see the condition of the spark plugs, however.  Nevertheless, I'll continue to ride it and enjoy it!  

Engine mods are: Sprint air filter, snorkel delete with expanded airbox lid hole, Akrapovic carbon racing line exhaust with baffle in,  2WDW flash.

[M. Hausknecht]

Just now, sweetscience said:

Yeah, my bike's right side exhaust pipe ( cylinder 2) seems to have a darker discoloration than the left side.  That side is running hotter for sure.  Since this is a by product of the limited tuning and CP2 engine characteristics, I am not terribly worried about it. 

Talking outta my a$$ here, because the CP2 has an uneven firing order, perhaps an ideal tune would require lambda sensors for each cylinder exhaust ports.  Instead of only using one O2 sensor to get the average for both.  But this is my speculation and could be false. 

Be that as it may, I had the ECU flashed to get a smoother, cooler running engine.  It will be interesting to see the condition of the spark plugs, however.  Nevertheless, I'll continue to ride it and enjoy it!  

Engine mods are: Sprint air filter, snorkel delete with expanded airbox lid hole, Akrapovic carbon racing line exhaust with baffle in,  2WDW flash.

Yes, two wide band O2 sensors would allow for individual cylinder  measuring of mixture, irrespective of firing order. Combined with capable hardware and software, one can tune the cylinders separately. The stock fuel maps call for varying amounts of fuel between the two cylinders for reasons I haven't been able to figure out (one cylinder is given more fuel at lower rpms and the other cylinder gets more fuel at higher rpms). What I have found when tuning a modified motor is that the stock disparities aren't justified but I haven't taken the step to two WBO sensors. I rely on plug reading with colder plugs than stock (I've found the stock plugs to be too hot to provide good reads in a modified motor) to evaluate the mixture differences between cylinders.  

[Triple Jim]

Just now, sweetscience said:

Yeah, my bike's right side exhaust pipe ( cylinder 2) seems to have a darker discoloration than the left side.  That side is running hotter for sure.  Since this is a by product of the limited tuning and CP2 engine characteristics, I am not terribly worried about it. 

My stock 2020's head pipes are so close to the same "straw" color that I can't tell any difference.

[sweetscience]

Just now, Triple Jim said:

My stock 2020's head pipes are so close to the same "straw" color that I can't tell any difference.

Yes, Yamaha has their stock tune dialed in.  But I always get all my bike's tuned anyways, because mods lol.

[sweetscience]

Just now, M. Hausknecht said:

Yes, two wide band O2 sensors would allow for individual cylinder  measuring of mixture, irrespective of firing order. Combined with capable hardware and software, one can tune the cylinders separately. The stock fuel maps call for varying amounts of fuel between the two cylinders for reasons I haven't been able to figure out (one cylinder is given more fuel at lower rpms and the other cylinder gets more fuel at higher rpms). What I have found when tuning a modified motor is that the stock disparities aren't justified but I haven't taken the step to two WBO sensors. I rely on plug reading with colder plugs than stock (I've found the stock plugs to be too hot to provide good reads in a modified motor) to evaluate the mixture differences between cylinders.  

I guess this special tuning can be left for the pro racers.  Probly out of the realm for the average moto enthusiast.

[M. Hausknecht]

Just now, sweetscience said:

I guess this special tuning can be left for the pro racers.  Probly out of the realm for the average moto enthusiast.

Or just amateur racers who can't quit messing with stuff. I wouldn't bother on a street bike; just give it a safe tune and ride it like you stole it!

[bootstrapjesse]

On 4/7/2022 at 8:36 PM, elykyle15 said:

Regarding the 16.8 MPG.

I reset this gauge and rode around in the city for a bit and the AVG doubled. Not sure if these numbers are acceptable for in-city driving.

Also, here's a video of me holding it around 3000-4000 RPMs.

Yeah... The AVE MPG thing is weird... Unless I/We don't know how to use it properly. I reset it when I fill up. Ive seen some stupid numbers on mine... Like 3.2. Obviously not correct. Best way is to actually do it manually. Just reset one of the trip meters when you fill up and calculate manually when you fill up next. I have the glowing pipe on cylinder #1 side as well.

[Triple Jim]

While it's better, 34 mpg still indicates an overly rich mixture, as does your glowing pipe.  Something is wrong.

[Andrew2791]

Any luck with this? I’m having a similar issue where the right cylinder (if sitting on the bike) is getting hotter. That pipe is turning blue while the left one has been always golden. I also have it tuned for the exhaust. After this started happening I noticed that on decel it’s popping like crazy and it’s a choppy sound when lowering the revs. It never did this before it always ran smooth on decel. 

Edited August 7, 2022 by Andrew2791

[M. Hausknecht]

Just now, Andrew2791 said:

Any luck with this? I’m having a similar issue where the right cylinder (if sitting on the bike) is getting hotter. That pipe is turning blue while the left one has been always golden. I also have it tuned for the exhaust. After this started happening I noticed that on decel it’s popping like crazy and it’s a choppy sound when lowering the revs. It never did this before it always ran smooth on decel. 

Who did the tune?

[Andrew2791]

Just now, M. Hausknecht said:

Who did the tune?

FTECU

[M. Hausknecht]

Just now, Andrew2791 said:

FTECU

The stock fuel maps provide more or less fuel to one of the cylinders for reasons I don't know, depending on rpm. I wonder what FTECU has  done to those differences. If I were building maps for sale, I'd use two wideband O2 sensors to be sure to get both cylinders running the same. You might ask if that is what they did. The different colors suggest otherwise. 

[Andrew2791]

Just now, M. Hausknecht said:

The stock fuel maps provide more or less fuel to one of the cylinders for reasons I don't know, depending on rpm. I wonder what FTECU has  done to those differences. If I were building maps for sale, I'd use two wideband O2 sensors to be sure to get both cylinders running the same. You might ask if that is what they did. The different colors suggest otherwise. 

It was never like this before about a month ago. For 3 years it ran smooth everywhere on acceleration and decel. The tune was perfect.

[M. Hausknecht]

So ok, then something changed, most likely with the fueling. My best guesses are fuel filter, fuel pump, and perhaps its time to clean or replace your fuel injectors. You might try pour-in-the tank injector cleaner first. If nothing changes or not enough, I'd empty and remove the fuel tank and pump. There is a mesh filter you can clean. Its pretty straight forward to do. You can send the injectors off to be cleaned or get new ones. I haven't heard and can't imagine how a tune could "go bad", so its likely something mechanical. 

[Triple Jim]

Just now, M. Hausknecht said:

So ok, then something changed, most likely with the fueling.

The strange thing is that whatever is wrong is adding too much fuel, which doesn't normally point to something clogged. 

[M. Hausknecht]

Just now, Triple Jim said:

The strange thing is that whatever is wrong is adding too much fuel, which doesn't normally point to something clogged. 

Yes, agreed but its fuel or spark, right? A dirty injector can fail to fully atomize the fuel, resulting in a delayed burn, that could be happening some in the pipe; that's my theory anyways. Sorta like an overly retarded spark resulting in mixture still burning when the exhaust valve opens.