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All 650's Will richer AFR make the engine cooler?

EuroBadger

2021
CB650R ABS
Feb 18, 2021
Riding Since
2019
My '21 CB650R is my first Euro 4/5 vehicle and it is hot as hell compared to the '15 CBR500R which I had previously owned. I know it's got more cylinders and displacement and all but still, hot is hot.
If I make the air-fuel ratio richer with something like the Booster Plug (it adds 6% more fuel at all rpms) will it actually cool down the engine? I've also heard richer AFR smoothes out the jerky throttle response when taking off.
 

Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
Riding Since
1993
Yes the engine does run cooler with more fuel. I found the same since fitting a PC5 with custom map.

Not sure on the jerkiness factor though, I put that down to blanking PAIR valves and adjusting throttle freeplay more than anything else.

J
 

EuroBadger

2021
CB650R ABS
Feb 18, 2021
Riding Since
2019
Yes the engine does run cooler with more fuel. I found the same since fitting a PC5 with custom map.
By how much? Can you actually feel it?
And I have no idea what blaking PAIR valves is... Gotta go googlin
 

EuroBadger

2021
CB650R ABS
Feb 18, 2021
Riding Since
2019
Ha... So my Euro5 ECU will flash a permanent warning light if I fit a BP to my '21 bike. Brilliant. Just brilliant.
 

EuroBadger

2021
CB650R ABS
Feb 18, 2021
Riding Since
2019
Ha... So my Euro5 ECU will flash a permanent warning light if I fit a BP to my '21 bike. Brilliant. Just brilliant.
If I ride around with the warning signal on my dash, am I going to miss the real warning in case some other part of my bike goes wrong?
 

Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
Riding Since
1993
Maybe. Knowing these bikes though, you'll not need the dash if something is really wrong... You'll hear/feel it first.

Did they say why you'd get a warning light? People have fitted power commanders without an light.

J
 

EuroBadger

2021
CB650R ABS
Feb 18, 2021
Riding Since
2019
Maybe. Knowing these bikes though, you'll not need the dash if something is really wrong... You'll hear/feel it first.

Did they say why you'd get a warning light? People have fitted power commanders without an light.

J
They say Euro5-ECU will flash a warning if it senses something tinkering with the air temp sensor.

 

MDM650R

2021
CBR650R
Aug 31, 2021
Riding Since
2020
I haven't fitted a Power Commander, went for a Woolich tune instead- However I was told by numerous tuning places that there's no PC's available yet for the 2021.
One good, reputable place that I asked said that they were able to cut and rewire a plug from the 2020 model, then make it fit a 2021.
Not sure if this is helpful, just some insight to 2021 650R power commanders.

Again, not sure if it's what you're looking for, but I got my bike Woolich tuned and now its running so rich that I can make the bike spit flames on command. So far after roughly 800kms and HARD riding, no engine lights or anything. Tuner de-activated my O2 sensor.

Maybe just go for a tune instead?

Although it will cost more, it's a lot easier.. They will fix your throttle response, and they're also able to change the ECU so the cooling fans come on a bit earlier, keeping your bike cooler overall, also, a tuned 650R is super fun.
 

ghehen

2018
CBR650F ABS
Jun 27, 2019
Vietnam
after plugged in pc5 with custom fuel map, you can definitely feel the difference of heat come from the engine. I think ecu flash can even more efficient, unlock the ecu can deliver more option on tuning the bike rather than pc5.
 

EuroBadger

2021
CB650R ABS
Feb 18, 2021
Riding Since
2019
Maybe just go for a tune instead?

Although it will cost more, it's a lot easier.. They will fix your throttle response, and they're also able to change the ECU so the cooling fans come on a bit earlier, keeping your bike cooler overall, also, a tuned 650R is super fun.
after plugged in pc5 with custom fuel map, you can definitely feel the difference of heat come from the engine. I think ecu flash can even more efficient, unlock the ecu can deliver more option on tuning the bike rather than pc5.
Euro5 regulations require the manufacturers to encrypt their 2021 ECUs so you can't flash them like you used to. I believe only a handful of garages have tried and succeeded at flashing the new ECU, like MDM650R said.
 

jef200

2019
CB650R ABS
Nov 28, 2021
Corsica
Riding Since
1979
My '21 CB650R is my first Euro 4/5 vehicle and it is hot as hell compared to the '15 CBR500R which I had previously owned. I know it's got more cylinders and displacement and all but still, hot is hot.
If I make the air-fuel ratio richer with something like the Booster Plug (it adds 6% more fuel at all rpms) will it actually cool down the engine? I've also heard richer AFR smoothes out the jerky throttle response when taking off.
I installed yesterday the BP/boosterplug on my Honda CB650R (2019 Euro 4 model).
I had already tested successfully this system on my 2 previous bikes.
It is very easy and quick to install, since you just need to unplug your ECU/airbox cable and plug the BP kit instead.
Your engine runs better and smoother, the response when you turn up the throttle is quicker, and even if the air/mixture is richer, you will not consume more fuel at the same revs.
BP improves neatly the gain I already got with my IXIL exhaust and my KN air filter. There are no more exhaust puffs when you turn down your throttle.
I had to spend 140 euros/160 USD for a BP, delivery by DHL is free and takes 2/3 days only from Denmark to Corsica.
Even if I can afford it, I will not pay any longer some 400 euros for a PC5 and 150 additional euros for a mapping on a Dynojet bench.
This is for racing use or pure pleasure, not for everyday driving in normal traffic conditions.
Pls note than BP is not compatible with Euro5 models (2021 and after).
 

Motojack

2021
CBR650R
May 26, 2019
Euro5 regulations require the manufacturers to encrypt their 2021 ECUs so you can't flash them like you used to. I believe only a handful of garages have tried and succeeded at flashing the new ECU, like MDM650R said.
did MDM650R say that though? 😕 Thought he was saying Power comanders for '21 were the issue.

I bloody hope we can flash the ECU on it, id like a tune myself.
 

JRinKtown

2018
CB650F
Jun 30, 2019
did MDM650R say that though? 😕 Thought he was saying Power comanders for '21 were the issue.

I bloody hope we can flash the ECU on it, id like a tune myself.
For what it's worth, aside from my cb650f I have a 2021 crf300l and the ECU can and is being flashed by at least one company. I have heard though, the European versions of the ECU cannot be flashed, at least by this company that flashes the North American versions.
 

MDM650R

2021
CBR650R
Aug 31, 2021
Riding Since
2020
The Euro5 ECU is harder to flash, and if you look around further in the forums - You'll see quite alot of people complaining about Engine Lights & T/C issues after getting an ECU flash. Seems to be even more of an issue with the LAMS/A2 restricted bikes.
When I got mine done in September '21, there were no Power Commanders available.

My tuner had tuned 2019 650R's in the past, but then had to buy a special plug/adaptor in order to tune my 2021 model.

This is very much just my own opinion based on all the issues i've read about online, but I'd honestly steer clear from a Flash if you can. Just find a good tuner who can map a custom dyno-tune onto your bike and you'll be laughing.

5000km later (hard riding, including track riding) - My Woolich tune has held up absolutely fine. No issues whatsoever. $880 AUD for me.
 

Motojack

2021
CBR650R
May 26, 2019
Thanks guys, getting my terminology mixed up. I assumed getting a custom map required an ECU flash.
 

MDM650R

2021
CBR650R
Aug 31, 2021
Riding Since
2020
Some would class them as the same, however I consider a 'flash' as more of a "plug & play" solution - its not really catered for YOUR bike, whereas a Dyno tuner will run 50+ runs to get your map perfect
 
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