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PAIR valve disabling


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This shows the simple and easily reversible "marble method" for disabling your PAIR valves. Please note that disabling your PAIR valves is not a performance modification, but is a good change to make when you have a Powercommander (and particularly an Autotune module) to get the best fuel mixture dialled in.

At this point, I will try and sell you Toro's PAIR block-off plates which I also have on order. These are a much better permanent solution and any money to Toro is a good thing because the bloke deserves it!

Anyway without any further ado, let's get started.

First, you need to get your seat off. I don't need to explain how to do that, but note that the tank cannot be lifted if the seat has not been removed.

Next, lift up the tank:

gallery_380_5242_96668.jpg

Remove the two 8mm bolts which secure the tank.

Once the tank bolts have been removed, lift up the tank and replace one of the bolts, like so:

gallery_380_5242_353250.jpg

Screw the bolt down a bit, then spin the washer so it seats against the frame.

We're going to use this bolt which is nicely sticking out of the frame as a means of securely holding up the tank. I have used some socket wrench extenders, with the hollow end sitting over the bolt head, and the solid end pushing up under the tank, like so:

gallery_380_5242_114431.jpg

Nice and secure!

Now we need to remove the UPPER air hose (it's the short one) from the rear-left of the airbox. This hose connects directly to the airbox and to the PAIR solenoid.

gallery_380_5242_373723.jpg

Remove the UPPER hose by loosening the clamps with your fingers and moving them down the hose. Use a small flat-blade screwdriver to wiggle the hose a bit to get it off.

Once it's been removed, your airbox should look like this:

gallery_380_5242_64969.jpg

Airbox without PAIR hose.

The next thing we need, is a bag of these:

gallery_380_5242_16737.jpg

Three dollar bag of assorted marbles!

Find a marble which is a nice tight fit in the hose but can be pushed with some effort. Note that it doesn't need to be the world's tightest fit - these are not vacuum hoses, just low pressure fresh-air hoses to draw air from the airbox into the exhaust. Don't be concerned about the marble being sucked into your engine! Firstly, there is very little if any air pressure going through these hoses, and secondly the marble will head towards the solenoid rather than the airbox, if at all!

SPECIAL NOTE: Feel free to test the marble by sucking on the hose. If you can successfully suck the marble out of the hose, put your tools down and go for a job interview in the porn industry. :pinocchio:

gallery_380_5242_235354.jpg

Push the marble into the hose, past where the clamps and hose connectors would reach to.

It's best to push your marble into the end of the hose which is straightest, so you're not trying to shove the marble round corners.

gallery_380_5242_161455.jpg

Marble goes in straightest end.

After this, you can just slip the hose back on, put the clamps back in their original positions, and secure the tank again. However we now need to adjust the idle speed, as the ECU holds the PAIR valves open during idling, which affects the airflow through the airbox and exhaust. Disabling the PAIR system causes the fuel mixture at idle to change and therefore the idle speed will drop, so we need to bring it back up.

Start the bike and let the engine warm up. If it won't hold an idle already, skip right ahead and perform the following step with the engine cold and also once it's hot.

We're now going to adjust the idle speed. Here's where the idle adjuster is on the right-hand side of the bike just behind the fairing.

gallery_380_5242_1700.jpg

Well hidden idle adjuster!

Turn the idle adjuster clockwise to increase the idle speed. Most likely it will be really hard to turn with your fingers, so use some needle-nose pliers if you like:

gallery_380_5242_84299.jpg

Be gentle and make small adjustments! A quarter turn can be a hundred rpm!

Once your engine is hot, and your idle has been set to approximately 1,200 rpm, you're ready to roll!

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gallery_380_5242_16737.jpg

thx kaldek - bloody good effort - might come in handy one day :fing02:

p.s. do i use a catseye or a stonker? :pinocchio:

Edited by TexOz
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Good write up.

Any particular reason for not unplugging the solenoid?

Also I would be interested to hear any theories on why the idle speed drops when the pair is disabled. In theory it shouldnt, but we all know it does.

I have my own theory but I would like to hear others.

Hint: You can largely restore the idle speed by making the mixture leaner at idle, ie-10% at 1250RPM and 1500RPM 0% throttle (but of course you need a powercommander for this)

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Any particular reason for not unplugging the solenoid?

Just to avoid any Fuel Injection (FI) light warnings. The service manual doesn't *have* a code for "faulty PAIR solenoid" though, so arguably you could disconnect it and have no errors on your FI system.

I'll be blocking my PAIR valves off with Toro's PAIR block-off plates in a couple of weeks, but I'll probably still leave the solenoid connected to avoid any electrical gremlins.

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I actually removed all the PAIR equip without any issues all the hoses and the solenoid valve too. No problems with 25000 miles on her. Just go to your local Napa autoparts store and get some rubber plugs and one cap for the airbox. I also got the block-off plates from Ebay... (not as nice as Toro's) So I would buy his if I had to do it over again. P.S. No FI errors after unplugging the solenoid.

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Y'know, I've tried a few times to disable the PAIR valves, and every time I've re-enabled them, because I reckon there's no significant benefit, and that the VFR doesn't run quite as well.

Same as the flapper valve, although in that case, what it does is flatten out the the hp/torque curve, so there's less of a kick at the point just after the flapper valve opens, which makes the engine seem comparatively flat and lifeless. IT's not, of course, but does change the character.

YMMV..

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We're now going to adjust the idle speed. Here's where the idle adjuster is on the right-hand side of the bike just behind the fairing.

Turn the idle adjuster clockwise to increase the idle speed. Most likely it will be really hard to turn with your fingers, so use some needle-nose pliers if you like:

Once your engine is hot, and your idle has been set to approximately 1,200 rpm, you're ready to roll!

There is actually a Phillips screw head inside the black plastic which you can use with a screwdriver (instead of pliers). I find that the easiest way to tweak my idle.

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We're now going to adjust the idle speed. Here's where the idle adjuster is on the right-hand side of the bike just behind the fairing.

Turn the idle adjuster clockwise to increase the idle speed. Most likely it will be really hard to turn with your fingers, so use some needle-nose pliers if you like:

Once your engine is hot, and your idle has been set to approximately 1,200 rpm, you're ready to roll!

There is actually a Phillips screw head inside the black plastic which you can use with a screwdriver (instead of pliers). I find that the easiest way to tweak my idle.

Oh yeah, there is too. Man I was even looking at the screw while I had the pliers in there, but must have had a couple beers too many to click.

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As kind of a side note here, on my '06 the PAIR solenoid never energizes after the bike gets warm (around 160 or so). After that, it just along for the ride. I actually connected a test light and rode around to figure this out (I also did this for the EVAP, but that's another tale). This would make sense because it's when the bike is cold that you have a bunch of unburned hydrocarbons. Adding a little oxygen would not only help continue the burning and use up some of those hydrocarbons, but this "extra" little camp fire will help heat up the CAT and O2 sensor. Besides, PAIR can't operate during close loop anyway. I would believe all 6th gen would operate this way and would be very surprised if 5th gen was any different.

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  • 1 month later...
Guest jimsuk

Do the pair valve block off if you’re running a PCV with Autotune. I just installed A&A Performance's plates and the difference was very noticeable.

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As kind of a side note here, on my '06 the PAIR solenoid never energizes after the bike gets warm (around 160 or so). After that, it just along for the ride. I actually connected a test light and rode around to figure this out (I also did this for the EVAP, but that's another tale). This would make sense because it's when the bike is cold that you have a bunch of unburned hydrocarbons. Adding a little oxygen would not only help continue the burning and use up some of those hydrocarbons, but this "extra" little camp fire will help heat up the CAT and O2 sensor. Besides, PAIR can't operate during close loop anyway. I would believe all 6th gen would operate this way and would be very surprised if 5th gen was any different.

Not sure if I agree with that. Popping from the exhaust on deceleration while the engine is hot was a common occurrence for me. Disabling the PAIR valves stopped that completely.

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Do the pair valve block off if you’re running a PCV with Autotune. I just installed A&A Performance's plates and the difference was very noticeable.

Totally agree with that! The AFR gets completely messed up when the PAIR valves open, totally snorking the Autotune trim tables.

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Sorry to be so uninformed but what do the Pair Valves do?

PAIR stands for Pulsed Air Injection Reed valve. It is a valve which sucks air from the airbox into the exhaust system when you are decelerating, and sometimes when idling. What it does is cause any unburnt hot gases to burn (or at least change chemical composition). It is an emissions thing to reduce nasties.

The reason folks disable it is to either merely avoid the popping and burbling when you decelerate, or to make their power commander tune work better. Particularly if you have an autotune module, the opening of the PAIR valve would cause the oxygen sensor to make fuel trim adjustments which are wrong and cause the bike to have a poor air/fuel mixture temporarily.

Honda Australia have advised customers with stock factory bikes in some cases to fit restrictors in their PAIR valve hoses, as some people have had throttle control issues due to the PAIR system. I personally never had that problem.

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As kind of a side note here, on my '06 the PAIR solenoid never energizes after the bike gets warm (around 160 or so). After that, it just along for the ride. I actually connected a test light and rode around to figure this out (I also did this for the EVAP, but that's another tale). This would make sense because it's when the bike is cold that you have a bunch of unburned hydrocarbons. Adding a little oxygen would not only help continue the burning and use up some of those hydrocarbons, but this "extra" little camp fire will help heat up the CAT and O2 sensor. Besides, PAIR can't operate during close loop anyway. I would believe all 6th gen would operate this way and would be very surprised if 5th gen was any different.

Not sure if I agree with that. Popping from the exhaust on deceleration while the engine is hot was a common occurrence for me. Disabling the PAIR valves stopped that completely.

I had the light(LED) connected for about for about 500 miles and I can tell you that the LED never lite above 160-ish. It's possible that pre-'06 or euro VFR's might be different. I've never had a reason to check the VFR, but most modern fuel injection systems actually cut off fuel when the throttle is closed for emissions reasons. That would make the operation of the PAIR on deceleration a useless venture. Kind of hard to have unburned hydrocabons without fuel(unless you have really bad rings and/or valve guides)

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  • 2 weeks later...
Guest Mysta2

It seems silly to me to go shoving marbles in things when you can just get rid of all this junk:

pair03.jpg

this is from my 94 BTW

pair04.jpg

and this is what you end up with:

pair02.jpg

The only reason I'd go through the trouble of it all would be to simplify and to save weight, again though, that's with a 94 with carbs. Those of you with the tuners are running a different setup. But why keep all the spaghetti? To fool the SMOG Gestapo?

Edited by Mysta2
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On my 5th gen, I installed Toro's blockoff plates and removed the entire PAIR system along with the solenoid.

No FI codes as there isn't one for the PAIR solenoid, so the bike doesn't even know it's missing.

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On my 5th gen, I installed Toro's blockoff plates and removed the entire PAIR system along with the solenoid.

No FI codes as there isn't one for the PAIR solenoid, so the bike doesn't even know it's missing.

I did the same thing on my 6th gen.

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  • 6 years later...
On ‎3‎/‎14‎/‎2010 at 5:34 AM, kaldek said:

This shows the simple and easily reversible "marble method" for disabling your PAIR valves. Please note that disabling your PAIR valves is not a performance modification, but is a good change to make when you have a Powercommander (and particularly an Autotune module) to get the best fuel mixture dialled in.

At this point, I will try and sell you Toro's PAIR block-off plates which I also have on order. These are a much better permanent solution and any money to Toro is a good thing because the bloke deserves it!

Anyway without any further ado, let's get started.

First, you need to get your seat off. I don't need to explain how to do that, but note that the tank cannot be lifted if the seat has not been removed.

Next, lift up the tank:

gallery_380_5242_96668.jpg

Remove the two 8mm bolts which secure the tank.

Once the tank bolts have been removed, lift up the tank and replace one of the bolts, like so:

gallery_380_5242_353250.jpg

Screw the bolt down a bit, then spin the washer so it seats against the frame.

We're going to use this bolt which is nicely sticking out of the frame as a means of securely holding up the tank. I have used some socket wrench extenders, with the hollow end sitting over the bolt head, and the solid end pushing up under the tank, like so:

gallery_380_5242_114431.jpg

Nice and secure!

Now we need to remove the UPPER air hose (it's the short one) from the rear-left of the airbox. This hose connects directly to the airbox and to the PAIR solenoid.

gallery_380_5242_373723.jpg

Remove the UPPER hose by loosening the clamps with your fingers and moving them down the hose. Use a small flat-blade screwdriver to wiggle the hose a bit to get it off.

Once it's been removed, your airbox should look like this:

gallery_380_5242_64969.jpg

Airbox without PAIR hose.

The next thing we need, is a bag of these:

gallery_380_5242_16737.jpg

Three dollar bag of assorted marbles!

Find a marble which is a nice tight fit in the hose but can be pushed with some effort. Note that it doesn't need to be the world's tightest fit - these are not vacuum hoses, just low pressure fresh-air hoses to draw air from the airbox into the exhaust. Don't be concerned about the marble being sucked into your engine! Firstly, there is very little if any air pressure going through these hoses, and secondly the marble will head towards the solenoid rather than the airbox, if at all!

SPECIAL NOTE: Feel free to test the marble by sucking on the hose. If you can successfully suck the marble out of the hose, put your tools down and go for a job interview in the porn industry. :pinocchio:

gallery_380_5242_235354.jpg

Push the marble into the hose, past where the clamps and hose connectors would reach to.

It's best to push your marble into the end of the hose which is straightest, so you're not trying to shove the marble round corners.

gallery_380_5242_161455.jpg

Marble goes in straightest end.

After this, you can just slip the hose back on, put the clamps back in their original positions, and secure the tank again. However we now need to adjust the idle speed, as the ECU holds the PAIR valves open during idling, which affects the airflow through the airbox and exhaust. Disabling the PAIR system causes the fuel mixture at idle to change and therefore the idle speed will drop, so we need to bring it back up.

Start the bike and let the engine warm up. If it won't hold an idle already, skip right ahead and perform the following step with the engine cold and also once it's hot.

We're now going to adjust the idle speed. Here's where the idle adjuster is on the right-hand side of the bike just behind the fairing.

gallery_380_5242_1700.jpg

Well hidden idle adjuster!

Turn the idle adjuster clockwise to increase the idle speed. Most likely it will be really hard to turn with your fingers, so use some needle-nose pliers if you like:

gallery_380_5242_84299.jpg

Be gentle and make small adjustments! A quarter turn can be a hundred rpm!

Once your engine is hot, and your idle has been set to approximately 1,200 rpm, you're ready to roll!

Hello! I Know this is an old post but hopefully you still see it and could help me out... I have 1 question--I do not have a power commander. I ride an 07 vfr and at low RPMs the front end kind of vibrates. It feels sort of like the wheels need to be balanced or something but I know its not the wheels that is the problem because once the bike goes up in Speed its fine. Could this PAIR Modification smooth out this issue on my bike?

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Anything that will smooth out the often poor low-rev fuelling on the 6th Gen is a good thing imo.

 

PAIR block-off helps, as does O2 elims & flapper removal, plus a clean zorst (and I don't mean recently washed) & cleaning the injectors.

 

Whether doing this will cure your problem you'll probably only find out if you do it, so because it's a good mod, just do it. :beer:

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3 hours ago, megatronousprime said:

Hello! I Know this is an old post but hopefully you still see it and could help me out... I have 1 question--I do not have a power commander. I ride an 07 vfr and at low RPMs the front end kind of vibrates. It feels sort of like the wheels need to be balanced or something but I know its not the wheels that is the problem because once the bike goes up in Speed its fine. Could this PAIR Modification smooth out this issue on my bike?

I have 08 with a PC5(map downloaded from here) and block off plates with the air box mod with set of Staintunes   and get 39 mpg with NO fueling problems.

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  • 1 year later...

Just a bit of add to this, it's a 16mm marble that's needed (0.62", whatever that turns into 342423/34234234 inch or something :P) (I put a tigershark marble in, makes me feel faster)

 

/R

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2 hours ago, RhINO said:

Just a bit of add to this, it's a 16mm marble that's needed (0.62", whatever that turns into 342423/34234234 inch or something :P) (I put a tigershark marble in, makes me feel faster)

 

/R

 

Hi - Why screw with marbles n stuff, just yank the damn thing outta there!

 

 

As a btw - I miss Kaldek and all his incredible detailed work he did on his bikes. Was great reading!

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