PAIR system removal / block off plate installation
Raising the front of the tank provides just enough room to get to both sides. The toughest part of this job is getting to the two inner bolts on each stock plate. Here's some pics along the way for those wondering how this is done. It's really much easier than it sounds.
1. Raise the tank by loosening this bolt, slide the tank back and raise the front. Use an appropriate sized piece of wood to support the tank. The tank wire will prevent it from coming up too far.
2. Remove the hoses on both sides.
3. Remove the valve that the hoses connected to in the triangular area of the frame and seal the electrical connection.
4. Remove the stock covers.
5. Remove these and insert them back the same way they came out.
6. Install a pair of semi_gray's beautiful block off plates with 6mm studs and acorn nuts or 6mm bolts. These will need to be a bit shorter than the stock ones - I found 18mm to be perfect.
7. Remove the hose going back to the air box and block off the air box nipple.
8. These are the removed parts you'll have at the end.
9. Enjoy the sound of your 919 decelerating without the annoying backfires.
__________________ 2009 Honda Goldwing Four wheels move the body. Two wheels move the soul.
Excellent writeup. This procedure will be added to the Helpful Topics from 919 owners.
Edit: A little background on the PAIR
The exhaust emission control system consists of a secondary air supply system which introduces filtered air into the exhaust gases in the exhaust port. Fresh air is drawn into the exhaust port whenever there is a negative pressure pulse in the exhaust system. This charge of fresh air promotes burning of the unburned exhaust gases and changes a considerable amount of hydrocarbons and carbon monoxide into relatively harmless carbon dioxide and water vapor. The PAIR system is controlled by the ECM using check valves and a solenoid.
Removal of the PAIR system will yield three main benefits: 1) reduction of engine compartment clutter 3) increase in the scavenging ability of the exhaust system 3) small weight reduction.
BTW - thanks to all those members that gave me some tips for this mod. All I really did was embellish what has been written in the past and add some pics. This forum rocks.
__________________ 2009 Honda Goldwing Four wheels move the body. Two wheels move the soul.
So if mine doesn't pop decelerating with aftermarket pipes on it (Yoshi's) is there any other benfit of this mod? Very nice write up. I do not have the PC3 on it yet either.
So if mine doesn't pop decelerating with aftermarket pipes on it (Yoshi's) is there any other benfit of this mod? Very nice write up. I do not have the PC3 on it yet either.
Well you lose about a pound of weight from the PAIR system removal and it does make it much easier to get to your spark plugs without those hoses in the way.
__________________ 2009 Honda Goldwing Four wheels move the body. Two wheels move the soul.
The only thing I'd take issue with (if you could call it that) is the part about
"Remove these [reed valves] and insert them back the same way they came out."
Why bother removing them if you're just gonna put em right back where they were?
Whassup with that?!
Actually, I'm just pokin' at ya. Do what you want with the reed valves but the plates were designed to utilize the boarder molded into the reed valves edges to seal the whole mess back up, just like factory.
I even popped some blind holes on the underside so the screw heads on the reed valves (you so nicely photographed) can live just proud of the gasket surface.
There's another write-up here about "snapping those little buggers off, but who cares?". I didn't want anyone to have to go through that kind of aggravation.
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I plan to die young, as late as possible.
The only thing I'd take issue with (if you could call it that) is the part about
"Remove these [reed valves] and insert them back the same way they came out."
Why bother removing them if you're just gonna put em right back where they were?
Whassup with that?!
Actually, I'm just pokin' at ya. Do what you want with the reed valves but the plates were designed to utilize the boarder molded into the reed valves edges to seal the whole mess back up, just like factory.
I even popped some blind holes on the underside so the screw heads on the reed valves (you so nicely photographed) can live just proud of the gasket surface.
There's another write-up here about "snapping those little buggers off, but who cares?". I didn't want anyone to have to go through that kind of aggravation.
Ya know, I looked at the reeds and noticed the gasket on them and decided that gasket would be good to keep on so I stuffed them back in the bike (with their screw fitting nicely in the blind holes of your plates) and put the plates on over them. And since there's nothing breathing there anyway, it seemed like it wouldn't hurt to keep 'em on. But I'm far from the expert on these. Should they stay or should they go? /me hums the Clash all of the sudden...
__________________ 2009 Honda Goldwing Four wheels move the body. Two wheels move the soul.
Should they stay or should they go? /me hums the Clash all of the sudden...
Keep 'em in there. They provide the seal.
If you take the reed valves out, you'd need to seal up the lip somehow to keep exhaust gases from escaping. It would no doubt need to be some robust sealant however and what have you gained, a few ounces?
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I plan to die young, as late as possible.
I do not want to pronounce s**** word here but I was wondering if anyone noticed more smoky exhaust after removing PAIR valves? I think that air pulses into do help to completely oxidize some combustion product on deceleration. It is tempting though to take extra tubes and parts off the bike..
Good chance you're right Serge. But if it kills the backfire, it's worth it.
FWIW - I went for a ride today and tried hard to get it to backfire on decel. I couldn't do it. Let the throttle snap closed from 6K and not a backfire to be found. LDH, moto, semi et al - you guys were right -- PAIR is the backfire culprit.
__________________ 2009 Honda Goldwing Four wheels move the body. Two wheels move the soul.
Great write-up. Thanks for doing this. Made this mornings chores a lot easier. I would like to inform everyone of a little hiccup that may be coming when you do this.
The right side removal and installation is a bitch. Make sure you have a 1/4 drive and socket and a universal or else you have to remove the coil as another step. I couldn't get to it with anything else.
Thanks Semi. I recieved my plates in the mail yesterday. Got them put on a while ago. It was a pita, but oh well, I'm done. It is one of those little details that give your bike a more professional look. I like em!
Great write-up. Thanks for doing this. Made this mornings chores a lot easier. I would like to inform everyone of a little hiccup that may be coming when you do this.
The right side removal and installation is a bitch. Make sure you have a 1/4 drive and socket and a universal or else you have to remove the coil as another step. I couldn't get to it with anything else.
Thanks also to semi_gray for the plates.
Very nice work all-around guys.
Both inner bolts were tough if you have hands bigger than 4" in diameter. This was the toughest part of the job and the most time consuming. The good news is with these hoses and valve gone, getting to the two inner spark plugs will be a little easier.
__________________ 2009 Honda Goldwing Four wheels move the body. Two wheels move the soul.
I don't believe there is a single 919 anywhere w/o the PAIR system. Folks across the pond just probably have stricter inspections that prevent the removal of the system.
__________________ 2003 919 27,000 miles
"racing is life...everything else is just waiting"
BTW - thanks to all those members that gave me some tips for this mod. All I really did was embellish what has been written in the past and add some pics. This forum rocks.
You also make a excellent finger model. Nice write up. Answered all my lingering questions.
The right side is a pain--I had visions of pulling the engine after I rounded the inner right side bolt. Luckily that fin part of the pair cap to the rear broke & then I could get on it with a box end wrench (6pt) & back it off---CLOSE CALL.
Plates fit like a glove & look great--lots more room & less useless parts.
Yes, they are a pain to put on. I think someone else said it, a universal is the way to go. I found an 8mm universal to save on height and it worked really well. Highly recommended, and at about $6, well worth the tool.
M6X1.
Fine thread M6 is .75
I used 18MM studs with Stainless Steel acorn nuts I bought at Ace Hardware.
Ace also has a decent supply of chrome hardware.
__________________
I plan to die young, as late as possible.
They are too short to use with the block off plates.
Actually, the stock bolts will be too long if used with the blockoff plates.
The factory flange measures .315". Round down to .312 and you have 5/16".
The plates I made were from 3/16" plate, or .187".
.312-.187=.125", or 1/8".
If you're going to be using the factory bolts, to be safe remove 1/8" of thread before re-using them being sure the threads are clean.
I like to thread a nut on the bolt before hacking away so the removal will help straighten out the threads.
__________________
I plan to die young, as late as possible.
I also picked up my OEM center stand from the dealer and I was intent on putting it on. But after reading the instructions I decided to put that on hold what with loosening the radiator and header along with removing the tail section and mufflers.
So I went after the PAIR system and really it was piece of cake. I used a wobble extension and a u-joint on the inner bolts. I highly recommend picking up both. It took me longer to figure out how the valve was mounted than removing the factory covers and putting SG's plates on.
This forum has been a great resource. Certainly more helpful then my dealer.
Sylas there is a 5 min install on the OEM c-stand. Maybe do a search. It involves removing part of the center brace. If you can't find anything on it maybe I can go into greater detail.
This procedure will be added to the Helpful Topics from 919 owners.
Good timing!
and it does make it much easier to get to your spark plugs without those hoses in the way.
'02 Honda 919 - She's the only one for me!
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