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All 650's PAIR Valve Removal

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MACB650f

2018
CB650F ABS
Jan 3, 2020
That's nothing to do with it. They are spacers/mounts for the air filter. You need to bung the hole at the front right of the airbox... Up the pointy end!

Opposite the one with the oily stuff around it.

J
Damn, I thought it were there... But it seems they have connection to a underneath channel below.
So it's the green one? What is the blue one? Some kind of drain for that oily residue? But aren't they outside the airbox chamber?
IMG_20200208_153154.jpg
 

MACB650f

2018
CB650F ABS
Jan 3, 2020
So the air that arrives from that "green" hole, goes directly from the outside to the engine? It's not filtered by the air filter?
 

MACB650f

2018
CB650F ABS
Jan 3, 2020
Sorry for last post, I think I understand now, the air comes, passes the filter and goes through that green hole to the valves, entering further in the system..
 

MACB650f

2018
CB650F ABS
Jan 3, 2020
Regarding the plug of the pair valve... Is there any issue of blocking the hole from the inside of the airbox with some sort of plug? Can that plug be sucked into the airbox and then enter the throttle body?
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Riding Since
1975
Regarding the plug of the pair valve... Is there any issue of blocking the hole from the inside of the airbox with some sort of plug? Can that plug be sucked into the airbox and then enter the throttle body?
Clean everything up around the area with alcohol and use tape over it if you are worried it may fall out. If it solves your issue, silicone it in place.
 

MACB650f

2018
CB650F ABS
Jan 3, 2020
Clean everything up around the area with alcohol and use tape over it if you are worried it may fall out. If it solves your issue, silicone it in place.
Just pretty scared that anything enters the throttle body, that will be the end of the story.. . I pretend to check the effects of the pair valve blocked first, and if it is OK I will plug it from below the air box or even ask the mechanic to take everything.
 

MACB650f

2018
CB650F ABS
Jan 3, 2020
So... blocked the air flow to the pair valves in the correct hole right now 😁. After a short ride, can say that it sounds better, the stutter is way lesser than before. It's still there but I think it's the nature of this BS throttle. Also the rumble at low rpm is more subtle than before and there's no more pop on upshift. Have to test along the next week for better comparison 😊
 

MACB650f

2018
CB650F ABS
Jan 3, 2020
BTW, the issue with the bung getting loose inside the airbox and possibly enter the throttle body, it's quite difficult because there is a flange on airbox cover that presses the rubber bung into the hole.
Thanks everyone for all the help.
 

Khalif

2016
CBR650F ABS
Nov 2, 2019
Get a set of JIS Screw drivers. Do NOT strip the air box intake funnels screws!
Hahaha I made this mistake, what and absolute hellish experience after stripping 3 of these little buggers. I had to drill and reverse thread the original screws to get them out.
 

FogDucker

2018
CB650F ABS
Apr 3, 2019
Canada
My “tick” doesn’t come from the tank area. Mine comes through the exhaust. I’m just convinced this is the way akrapovic designed their exhaust and it’s the way it’s supposed to sound. Paid $1,000 to hate my exhaust. *smiles*
check out my post at page number 10 and let me know if the buzzing/ticking is the same u hear in the video
 
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CBRHarrison

2017
CBR650F ABS
Mar 14, 2020
Riding Since
2000
Can anyone tell me the best way to block the reid valve from within the airbox.
I'm confident I can blank it off properly with the ebay blanking plates but would rather go with the path of least resistance if possible i.e. shoving a rubber bung into the airbox pair valve tube. What diameter bung is required?

My main aim with this mod is to reduce the throttle jerk from fully closed to slightly open, I currently have my throttle free play and chain slack at the minimum recommended settings and there is still a noticeable jerk no-matter how smoothly I open the throttle. (It is really putting me off the bike tbh)

I'm not sure if it will have an effect but the bike is a 2017 with a full termignoni exhaust system on (road legal model but no cat), throttle response is the same with or without the DB killer installed into the exhaust
 

baugustine

2014
CBR650F
Staff
May 21, 2016
Ventura, CA
CBRHarrison @CBRHarrison I’m unsure of your question above. The reed valves are inside the covers on the engine, not in the airbox itself. There are two hoses from the airbox. The left side one is the PCV valve, and the right side one goes to the PAIR solenoid. To eliminate the PAIR you have to blank it off. You can either drill some dimples in the bottom side of the block-off plates or remove the reed valves brackets themselves. Does this answer the question?
 

CBRHarrison

2017
CBR650F ABS
Mar 14, 2020
Riding Since
2000
You should be able to achieve the same effect by blocking this hole with a rubber bung stopping the pair valve from being able to vacuum air from the airbox?

That’s my theory anyway, obviously removing the pair valve and blanking it off would be better but I’ve just been in the garage for a look, got carried away and ended up doing the job with a rubber bung down this hole, I’m hoping this solves my off/on throttle snatching. I will get the blanking plates ordered if I notice an improvement and replace the rubber bung when the spark plugs are due
(I’ve made sure to use a bung that could not get drawn through and ingested into the engine in anyway)
5845AEBA-88C2-4B94-88BB-7B52F4469D20.jpeg
 

CBRHarrison

2017
CBR650F ABS
Mar 14, 2020
Riding Since
2000
CBRHarrison @CBRHarrison I’m unsure of your question above. The reed valves are inside the covers on the engine, not in the airbox itself. There are two hoses from the airbox. The left side one is the PCV valve, and the right side one goes to the PAIR solenoid. To eliminate the PAIR you have to blank it off. You can either drill some dimples in the bottom side of the block-off plates or remove the reed valves brackets themselves. Does this answer the question?

Ah! Sorry I see the confusion now I have mixed up pair and reed valve terminology!
 

FogDucker

2018
CB650F ABS
Apr 3, 2019
Canada
You should be able to achieve the same effect by blocking this hole with a rubber bung stopping the pair valve from being able to vacuum air from the airbox?

That’s my theory anyway, obviously removing the pair valve and blanking it off would be better but I’ve just been in the garage for a look, got carried away and ended up doing the job with a rubber bung down this hole, I’m hoping this solves my off/on throttle snatching. I will get the blanking plates ordered if I notice an improvement and replace the rubber bung when the spark plugs are due
(I’ve made sure to use a bung that could not get drawn through and ingested into the engine in anyway)
View attachment 5785
I used blue tick as a temp solution to see the result. I also taped it off with a piece of electric tape. Haven’t had a chance to ride but throttle response felt like buttery smooth after my short spin at my building’s garage

3F7F9056-655F-43A7-A4DB-BE91E6C68ED1.jpeg
 
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FogDucker

2018
CB650F ABS
Apr 3, 2019
Canada
Can anyone tell me the best way to block the reid valve from within the airbox.
I'm confident I can blank it off properly with the ebay blanking plates but would rather go with the path of least resistance if possible i.e. shoving a rubber bung into the airbox pair valve tube. What diameter bung is required?

My main aim with this mod is to reduce the throttle jerk from fully closed to slightly open, I currently have my throttle free play and chain slack at the minimum recommended settings and there is still a noticeable jerk no-matter how smoothly I open the throttle. (It is really putting me off the bike tbh)

I'm not sure if it will have an effect but the bike is a 2017 with a full termignoni exhaust system on (road legal model but no cat), throttle response is the same with or without the DB killer installed into the exhaust
 

MrFritz86

2019
CB650R
Sep 28, 2019
Nashville, TN
Hello everyone

So today I did blank the PAIR valves with the smart moto kit available from ebay, tomorrow the SC Project Dual CRT will be delivered and will be doing it over the weekend.
Not sure if I did the best thing to have it done it right now, instead of doing it after the installation of the new exhaust, but I did a 30 minutes test ride and felt better.

I was also able to completely remove the solenoid valve, I've used 27Ohm resistor 1/4W 5% tolerance to avoid having any engine light on the dash.

Everything worked out pretty well, it took me like 2 hours by myself, had to figure out a bit on how to make room to work around it, so if anyone is planning on doing it on CB650R, my best way was to remove the 2 air intake shrouds to be able to reach the bolts and have room to move the tools.
Had to curse a bit putting back the air conducts on the air-box, so another suggestion is to do not remove the conducts from the box itself, the conducts are made of 2 pieces so they can be split, one half stays on the box and the the other attached to the intake shroud.
So when removing the air box and the intake shrouds make sure to split the conducts.
This is probably shown on the shop book, which I own but I probably missed that point.

I've removed the reeds even though the block off plates are the new one (no need to drill recesses) bc I thought they would vibrate around 4000rpm.

The engine doesn't sound crazy anymore around 4k and it felt a bit smoother, throttle response less aggressive and the engine doesn't stutter, engine brake a bit softer as well, also the overall sound of the engine/exhaust was better even with the stock exhaust. Maybe since that "bag of bolt" sound is gone. That sound was pretty annoying to me and finally I got rid of it.

Be posting some update for the Sc Project in other exhaust thread.

Thanks to everyone for info in this thread, it was really helpful.
 
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