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CBR650R Possible leaning issue

Joeiom

2020
CBR650R ABS
Jan 23, 2022
Riding Since
2020
I recently had a Austin Racing de-cat Gp1R system installed, however i don’t know if it leaning out or not, I see guys online revving out to 12k without issues, but mine breaks up/hits a limit at 10,800, any ideas? Bike isn’t remapped and has no other performance mods
 

Joeiom

2020
CBR650R ABS
Jan 23, 2022
Riding Since
2020
High probability you are running out of fuel at that RPM with a stock tune and low-resistance exhaust.
That’s what i’m thinking, annoyingly they specified no additional tuning is required, I’ve brought this up with them and they are adamant it’s not caused by their exhaust
 

baugustine

2014
CBR650F
Staff
May 21, 2016
Ventura, CA
That’s what i’m thinking, annoyingly they specified no additional tuning is required, I’ve brought this up with them and they are adamant it’s not caused by their exhaust
I did not have to tune my 650F when in installed the full Akra exhaust but I definitely had to remap my VFR with the aftermarket exhaust. I think it depends on the fueling parameters in the stock tables combined with the amount of increased airflow of the upgrade compared to the OEM.
 

Joeiom

2020
CBR650R ABS
Jan 23, 2022
Riding Since
2020
I did not have to tune my 650F when in installed the full Akra exhaust but I definitely had to remap my VFR with the aftermarket exhaust. I think it depends on the fueling parameters in the stock tables combined with the amount of increased airflow of the upgrade compared to the OEM.
This has quite a lot more airflow over the stock one, so as you say, it may be the case the fuelling can’t keep up with it in the higher rpm, would you say it’s safe enough to ride around on if it’s only seems to be affecting in high rpm’s? The bike runs like normal any other time and the throttle response is the best it’s ever been
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Riding Since
1975
This has quite a lot more airflow over the stock one, so as you say, it may be the case the fuelling can’t keep up with it in the higher rpm, would you say it’s safe enough to ride around on if it’s only seems to be affecting in high rpm’s? The bike runs like normal any other time and the throttle response is the best it’s ever been
Did you replace the 4 exhaust manifold gaskets when installing? Are you positive you don't have any air leaks? Sounds to me like you might have an air leak.
 

baugustine

2014
CBR650F
Staff
May 21, 2016
Ventura, CA
This has quite a lot more airflow over the stock one, so as you say, it may be the case the fuelling can’t keep up with it in the higher rpm, would you say it’s safe enough to ride around on if it’s only seems to be affecting in high rpm’s? The bike runs like normal any other time and the throttle response is the best it’s ever been

If you rule out the exhaust leaks per miweber929 @miweber929 above then you will be fine running it. I installed a PC-V on my VFR and did some tuning of my own with the laptop. You may want to consider adding fuel in the higher RPM cells of the tables if its still breaking up. How many miles on the motor so far?
 

Joeiom

2020
CBR650R ABS
Jan 23, 2022
Riding Since
2020
Did you replace the 4 exhaust manifold gaskets when installing? Are you positive you don't have any air leaks? Sounds to me like you might have an air leak.
I had the exhaust fitted by a garage, they are quite an*l about things so I would hope they did replace the manifold gasket, but i’m not sure without asking. I have had a look round the system and from what I can see, there is a rather small exhaust leak where the Austin racing attaches, but i’m not sure if they can close it up anymore than it is as you have to cut the factory one to fit this, so the surfaces might not match up fully, but it is quite small and idk if it’s enough to freak it out, it’s quite close to the O2 sensor, but again I don’t think it’s enough to cause the leaning this hard, especially when it’s only at wide open throttle, there should be enough exhaust gas flowing at full chat to stop it sucking in any air
 

Joeiom

2020
CBR650R ABS
Jan 23, 2022
Riding Since
2020
If you rule out the exhaust leaks per miweber929 @miweber929 above then you will be fine running it. I installed a PC-V on my VFR and did some tuning of my own with the laptop. You may want to consider adding fuel in the higher RPM cells of the tables if its still breaking up. How many miles on the motor so far?
Well that’s good at least, I can still ride it without worrying about grenading the motor, off the top of my head it’s on 2310 ish miles, only had the exhaust for like maybe 5/10 of those miles
 

Enrico

2018
CB650F ABS
Mar 28, 2019
I recently had a Austin Racing de-cat Gp1R system installed, however i don’t know if it leaning out or not, I see guys online revving out to 12k without issues, but mine breaks up/hits a limit at 10,800, any ideas? Bike isn’t remapped and has no other performance mods
Yes ,don't rev it so high ,never used to take myCB650F anywhere near 10,800 rpm !
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Riding Since
1975
I had the exhaust fitted by a garage, they are quite an*l about things so I would hope they did replace the manifold gasket, but i’m not sure without asking. I have had a look round the system and from what I can see, there is a rather small exhaust leak where the Austin racing attaches, but i’m not sure if they can close it up anymore than it is as you have to cut the factory one to fit this, so the surfaces might not match up fully, but it is quite small and idk if it’s enough to freak it out, it’s quite close to the O2 sensor, but again I don’t think it’s enough to cause the leaning this hard, especially when it’s only at wide open throttle, there should be enough exhaust gas flowing at full chat to stop it sucking in any air
Wait, so this is a cut your stock and put this on as a muffler thing? Yeah, I wouldn't trust that to seal well so I am not surprised.
 

motorider

2019
CBR650R ABS
May 6, 2021
Riding Since
1986
I recently had a Austin Racing de-cat Gp1R system installed, however i don’t know if it leaning out or not, I see guys online revving out to 12k without issues, but mine breaks up/hits a limit at 10,800, any ideas? Bike isn’t remapped and has no other performance mods

I have the 2019 US model, the ECU has a soft limit of 11,200 rpm and you may have a similar limit on your bike's ECU. I suggest finding a local shop to tune it and raise the rpm limit to 12,000 then dyno test it and see what the results are. I attached the last dyno run of my bike and you can see the limiter kicks in at 11,200.
 

Attachments

  • 2019 Honda CBR650R Akra Tuned 121621.pdf
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