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Another question : wouldn’t a bike that’s running too lean run hotter ?
Like I said I too was shocked to find the bike ran better snd cooler after decat and even better after the sprint filter.
Last question does the pair valve system affect o2 sensor readings??!!! Got so many mixed answers on this question. Guy from woolich said the o2 sensors will work just fine WITHOUT the pair valve pump and with block off plates. Thanks guys !
 

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Yes a richer afr helps with the operating temps, when you get the reflash the PAIR is disabled.
If you’re going to Dyno your bike it’s a must so that you get a accurate reading
 

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Yes a richer afr helps with the operating temps, when you get the reflash the PAIR is disabled.
If you’re going to Dyno your bike it’s a must so that you get a accurate reading
Not heat soaking the engine by having it exhale through a 7lb honey comb lowers the overall heat in the engine because it can breathe. I mean, fattening one up will work too, but with a cat in place it would bog running rich enough to do anything meaningful.

The pair probably has something to do with the narrow band sensors and the lean condition after removing the cat. Likely the reason the engineers do what they do on bikes. That, is conjecture on my part. A guess.
 

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Your all focused on fuel.... the timing and throttle maps matter a ton for the tune too....a flash is way more than simply re-writing the fuel map.

Popping is usually due to a lean condition... and if you popping on deceleration your tune could use off throttle tuning. Most dyno tunes don't tune off throttle, because your only going to get that from data on the road/ track.
 

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also I don’t think anyone in here DOESNT want to spend the money on a tune it’s just that it ISNT available for the 2020 and 2021 r1. I’m sure most of us in here would pay much more in a heartbeat to have a flash available
This is where this whole thing has gotten blurred. There are options to tune the fueling of the bike, at least 4 of them and have been for most of last year. The "issue" is the ecu can't be flashed so built in restrictions (throttle, max speed, etc....) can be removed. At some point people have combined the two and now say the bike can't be tuned, which isn't the case. As for leaner with or without a cat , I'm not a mechanic and don't claim to be so I can't really speak on it. That blarb from Revilla doesn't mean anything. So yeah the bikes will run without the cat but doesn't mean they should. When I've removed the cat, AIS, etc...... all of my bikes had the same reaction and that was the exhaust pop, smell of fueling, and other signs that the bike was set to run in that way. My 05 R1 had the least reaction but my 2016 R6 had the worst

Again every dyno run I've seen posted showing before and after a stock exhaust has been removed has shown it to run lean. I saw that when my 2020 was put on the dyno. How different bikes react to running lean varies. I got a warning from a friend about the 2020 R1 and he's never warned me about any of my other Yamaha's. So I chose to take his word as he works for Yamaha. Saying my bike runs "better" is also very subjective.because it may "feel" like it runs great when it actually doesn't. I had a map put on my R6 and thought it ran "better" and then I actually had my R6 tuned and saw a huge difference in how the bike ran. Comparing the dyno output was night and day.
 

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I understand. When I say “my bike runs better” I mean better than with cats NOT better than a tune. I said a tune gets the best performance a few times, at least. Also as far as the bike being lean ..they come lean from the factory for emissions and fuel economy. The honeycomb cats burn any unburned fuel left over after combustion and the pair valves help facilitate that burning.

So actually the engine is popping and running lean even with the cats but you just won’t hear the popping due to the cats.
 

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I understand. When I say “my bike runs better” I mean better than with cats NOT better than a tune. I said a tune gets the best performance a few times, at least. Also as far as the bike being lean ..they come lean from the factory for emissions and fuel economy. The honeycomb cats burn any unburned fuel left over after combustion and the pair valves help facilitate that burning.

So actually the engine is popping and running lean even with the cats but you just won’t hear the popping due to the cats.
For sure it's not working better now than with cat. Or better yes after 6-7000rpm. But under that not so great, you just got used to it.
Just opening the exup with stock exhaust it launches shit and you feel how lean the bike is at low rpm.

It's nearly at 16 afr at some low rpms with de cat..
 

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Well I can only speak from my own experience. When I got the bike it was so slow and quiet I almost regretted buying. I was coming from a Zx10r which seemed MUCH faster. I then did the decat and it was like a totally different bike. Saved the day.
Now I love the bike snd the cross plane engine and sound. The handling is the best of any bike I’ve been on. Feels like a 650 not a 1000 handling wise.

but to your point I don’t really do much slow or stop and go riding. I’m rarely in the 1k to 6k rpm range. The bike isn’t made for that IMO.

the back pressure of the cats and valve does create more torque supposedly on the bottom end but again I’m not ever in that range.

as far as thebike running lean I am aware of that.they are set lean from the factory ESPECIALLY for stop and go local riding ie 1-6k rpm.
 

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Can't tell you how slow the r1 20 is in us, but here in Spain i put it on dyno before 1000miles and it made 182 or 184 at the wheel.

And yes it's not made for driving slow and a customer has it as a trackbike with straight pipe no tune, and works ok. But transitions are shit and in some corners your rpms at the apex is shit also and is much better with cat connected.

The eu bike makes about 10hp more at certain rpm without cat, but as I said transitions are shit and low rpm and you are destroying the engine. It's just matter of time when it will be fucked.

If you want to make power, do the race ecu plus tune, it's possible with oem wire harness as I described before and you will have around 200hp at the back wheel.
 

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LOL I’m only in the 1-6k rpm range when I’m getting on or off the highways haha. Driving the r1 slow and locally would be torture !
 

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also I don’t think anyone in here DOESNT want to spend the money on a tune it’s just that it ISNT available for the 2020 and 2021 r1. I’m sure most of us in here would pay much more in a heartbeat to have a flash available
You can - get the GYTR ECU.
 
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