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CB650R Dynojet Power Commander V Issue/Question

jrm072

2019
CB650R ABS
Jul 19, 2021
Riding Since
2021
Hello all,

Background: I am new to using a power commander/ modifying my bike. I recently installed the R77 Yoshimura Full Exhaust on my 2019 CB650R. Still with stock air filter. I was worried about running lean so I purchased the PCV and uploaded as close a map I could find to this setup (it was for an arrow full exhaust with stock air filter). I worked fine (albeit very rich) for two weeks. I then went on a trip to the mountains nearby and as soon as I reached around 3000ft in elevation the bike began to sound like it was misfiring. Unplugged the PCV and the bike ran well again.

My Question: What is the best route to getting the bike tuned or mapped that actually implements the use of the O2 sensor to adjust for elevation changes?

Apologies if this has been answered on here already, I could not find any post specifically for this issue.

Thanks in advance!
 

MrFritz86

2019
CB650R
Sep 28, 2019
Nashville, TN
Hello there

getting the PCV properly tuned will help for sure, this will keep the AFR as close as possible to stoichiometric standard, the lambda sensor is constantly working, if the AFR is wrong to begin with then any air density, air temperature changes will affect even more the way the engine responds.
Also consider that, if the tune map is being done at a certain altitude and temperature (for example at sea level), certain time of the day, it will be different if you get to higher altitudes at different time of the day, since the air density is different.

Yes the lambda sensor should compensate for that, but considering it's a narrowband (tipicallly 0.99 to 1.01 Lambda) not sure how much it will be able to do so.

I do have a PCV as well, and even without it I could tell the difference by riding at different times of the day.

Beside the engine misfiring, which is pretty common with aftermarket exhaust to be heard more than the OEM Cat Exhaust, did the engine perfom bad?
 

jrm072

2019
CB650R ABS
Jul 19, 2021
Riding Since
2021
What would be the best method for me to tune the PCV properly? There were only 6 maps listed on the Dynojet site. Is there another route?

I've done the trip before with OEM exhaust and normal ECU setup. Handled it no problem. As for this time, once I disconnected the PCV the engine performed perfectly fine. Slightly less power if anything. I did not ride more than a few hundred feet once I heard the misfire.
 

MrFritz86

2019
CB650R
Sep 28, 2019
Nashville, TN
What would be the best method for me to tune the PCV properly? There were only 6 maps listed on the Dynojet site. Is there another route?

I've done the trip before with OEM exhaust and normal ECU setup. Handled it no problem. As for this time, once I disconnected the PCV the engine performed perfectly fine. Slightly less power if anything. I did not ride more than a few hundred feet once I heard the misfire.
the best method is a dyno tune specialist. but it can cost a little bit $$$, it could be something in between $300 and $500 it depends where you go and what price they offer.

Is the PCV connected now? or still disconnected?
Make sure to test it again if still disconnected, maybe it's not working properly.
Check that it's working fine riding the bike in your area.

if the PCV works properly and the engine was misfiring at a higher altitude, and not the pops heard from the exhaust, then I would get a proper tune and test it again.
I would get it anyway if I was you. Unfortunately here there aren't any shops (beside one that is never available and is asking you to leave the bike at his shop for unknown amount of time).
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Riding Since
1975
You don't need a PCV with that setup, I'd pull it, sell it and run the bike as is. It will live a long, very happy life in that state.

Or find a tuning shop, pay them $400 to build you a custom map which will net you very little. Your call.
 

jrm072

2019
CB650R ABS
Jul 19, 2021
Riding Since
2021
the best method is a dyno tune specialist. but it can cost a little bit $$$, it could be something in between $300 and $500 it depends where you go and what price they offer.

Is the PCV connected now? or still disconnected?
Make sure to test it again if still disconnected, maybe it's not working properly.
Check that it's working fine riding the bike in your area.

if the PCV works properly and the engine was misfiring at a higher altitude, and not the pops heard from the exhaust, then I would get a proper tune and test it again.
I would get it anyway if I was you. Unfortunately here there aren't any shops (beside one that is never available and is asking you to leave the bike at his shop for unknown amount of time).
I think this is what I'm going to do. I have it disconnected and going to return it and get another new one. If that doesn't seem to fix it I'll most likely run without a PCV at all
 
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