How-To: PAIR removal for 5th Generation

How-To: PAIR removal for 5th Generation VFR

I've got an 2001 VFR800 and I couldn't find any How-Tos on removing the PAIR, so I put together this How-To and hopefully someone else will find this useful.


1. Remove the seat.

2. Remove the two front bolts on the gas tank.

3. With a hammer/wood, or something of sufficient strength to hold the tank up, tilt the gas tank backwards and put the hammer/wood between the tank holes and frame.

4. Remove the connections to the two breather tubes that are connected to the gas tank. They should come off fairly easy. One is on the left side of the bike close to the gas tank pivot, and the other is on the right side of the bike, and runs down into the frame with a white/clear elbow joining the two hoses.

5. Disconnect the two electrical connectors (the white one is for the fuel pump, the other is for the fuel gauge).

6. Tilt the tank back down onto the frame.

7. Remove the two rear 10mm bolts attaching the gas tank to the pivot.

8. With a table or milk crates (something with sufficient strength and height) to the
right of the bike, lift the gas tank off of the bike and place on the table. Careful not to rest the tank on the plastic faring or rear cowl. This step allows you to work freely in the airbox/intake area without the gas tank obstruction.

9. Remove the back five screws from the airbox. Loosen the front two screws and the hose to the diaphragm on the top of the airbox. Remove the screw to the PAIR valve mounting bracket arm (gold), and remove the airbox cover.

10. Remove the air filter.

11. Remove the four plastic air inlets. I used an electric drill with a phillips end to zip them out quickly.

12. Remove all four intake vacuum hoses from the airbox. There should be two per side. These are used in the California models, but in non-California models they just are plugged.

13. Remove the large crankcase ventilation tube from the rear of the airbox. It runs from the top/front of the rear valve cover to the airbox.

14. Remove the plastic electrical connection to the solenoid, located directly below the hose just removed.

15. Remove the vacuum tube going into the bottom of the solenoid.

16. Remove the two screws and the self-locking nuts holding the two coils for the rear cylinders to the airbox. Move the coils aside.

17. Lift up the rear of the airbox and remove the two rubber hoses attached to the bottom of the airbox.

18. Remove the electrical connection to the airbox temperature sensor, located to the side of the two rubber hoses.

19. Now the airbox can be lifted up even higher. On the front/right/bottom of the airbox, remove the vacuum hose attached to the solenoid. You will need some dexterity to remove the hose.

20. Remove the large PAIR hose connected to the front of the airbox.

21. Remove the final vacuum hose on the front canister of the airbox.

22. Remove the airbox bottom.

23. This picture shows the PAIR hoses running on the left side of the motorcycle, the PAIR solenoid, and the pair front two PAIR hoses.


24. Disconnect the rear PAIR hose from the PAIR reed valve cover shown in this picture:


25. Disconnect the front PAIR hose from the front PAIR reed valve cover.


26. Remove the bolts from the left faring, enough to remove the PAIR electronic solenoid connection.


27. Disconnect and remove the PAIR assembly (hoses and solenoid).


28. Now you will see the PAIR reed valve cover clearly on the front cylinder.


29. At this point, you can either replace the PAIR reed valve cover, reeds, and plates with a PAIR replacement “kit”, which is just a flat piece of aluminum, or insert vacuum caps to disable the system. When installing the kit, be sure to clean up the mating surfaces and you may want to apply some silicone seal to the surface. To install the kit: With an 8mm socket, remove the PAIR reed valve covers.


You will now see the reed valves, with an orange/red gasket around them. With a screwdriver, you can pry out the reed valves.


Then, with needle-nose pliers, remove the metal plates under the reed valves.


Clean off the perimeter of any carbon, put silicone seal down, and then the reed cover plate. At this point, and this is recommended, you will want to ensure the covers are not leaking. Move the tank back into position, connect the fuel pump, and start the engine. Feel for any leaking of air coming from the perimeter of the metal plates.


30. If it is leaking, you may run into the situation where the machining of the PAIR casting is not perfectly flat, or if you do not want to buy the flat PAIR aluminum plates, you can still disable the PAIR system. You can simply cut the hoses coming out of the PAIR reed valve covers and put a vacuum cap into the hose. This will work because the reed valves prevent any gases from escaping and blowing out the vacuum cap, so they will have suction only, and very little. I bought this at Advanced Auto Parts and it fits snugly in the hose.

Vacuum caps:


Vacuum cap in PAIR hose:


31. Now put it back together in reverse order (airbox, vacuum hoses, coils, intake inlets, filter, airbox top, tank) and you are done! Be sure to keep disconnected and plug up the vacuum hose going to the diaphragm on the top of the airbox.

 

awesome!! I owe you a beer!

 

Sounds good. :smile:

 

I had issues with mine leaking around the plates, I had a post up about it a while ago. I think stoshmonster advised the best way to do it is to use the reed plates and the orange seal rings to seal the blockoff. If you take the little screw out of the the reed plate and remove the reed the plate will sit flush in the opening. Now the blockoff plate seals against the rubber seal like the pair system did. No sealer required. Hell of a nice write up you did there though. Getting to the rest of the system and detaching it can be a pain.

 

What's the end result here?

Power?

Fuel Economy?

Better Sound?

KC-10 FE out...
lane: :usa2:

 

Well, as I noticed on mine, the bike runs noticeably smoother at lower rpms, and doesn't backfire excessively on decel anymore.(aftermarket exhaust) I didn't notice any change in fuel economy.

 

Thanks for the great show and tell.
I'm with KC-10 what's the reason and what is the PAIR valve supposed to do for the bike when hooked up and working. Is it an emission control of some sort?

Thanks

 

PAIR stands for Pulse Air Injection Reduction. Essentially is uses the venturi effect to draw fresh air out of the airbox and into the heads right as the hot exhaust gasses are exiting the cylinders. The fresh air then allows the hot exhaust to continue to burn off unburned fuel, reducing hydrocarbon emissions. Unfortunately the reed valves allow some exhaust gasses to enter the air box assembly and the continuing combustion taking place in the exhaust system can cause annoying backfires on bikes with aftermarket exhaust systems. Hope the explanation helps, some form of this system has been used on cars as well, although not much recently.

 

The PAIR system works. But I didn't think it was for the unburnt fuel but more for the NOX emmissions or something like that reduces the formation of it. Could be a combination of both.

Most riders just find it annoying though.

 

I also found the bike runs smoother at lower rpms. I have the stock exhaust on it.

I did have a problem when i tried to just use the sealing of the orange gaskets of the reed valves with the blockoff plate. The aluminum piece i used didn't crush the reeds enough to reach the head, so I just left the front one on and plugged it up. The rear one worked like a charm, though.

 

You have to remove the reeds from the plates, theres a little phillips head screw holding each one together.

 

I didn't see why the reeds needed to be removed because they faced downwards and didn't interfere with the top plate, and I removed the metal-holed plate below it in case it wasn't sinking in fully. The orange gasket looks like it rests in the machined head casting, unless I'm missing something?

 

Nice tutorial. Thanks for your efforts..

 

Thanks for the write up. My only concern is how blocking off the PAIR system could have effect on the cat. I'm tempted to fit blocking plates...

 

Okay.. need your help!
I just did this and now when I start the bike it doesn't idle correctly (dies out). When I start it and give it throttle, it will throws the FI light and then finally idles at 1.5-2K rpms..

Anyone know what happened? We pulled everything and capped the reeds and also capped the inlet to the airbox from the PAIR.

 

I did this a little while back. The plates I bought from somewhere didn't work, I couldn't get them to seal, do I ised the sock parts with 5/8" caps. I couldn't get the air cleaner off (not patient enough to take it all apart I guess) so I worked from the front and side. Was really a pain in the ass, and it has been raining/snowing since, so I don't have a ride report.

 

Make sure all your hoses are connect back up.. lol

 

All; I did this a couple of years ago. It's vitally important!! that you plug the hose connection at the air box where the PAIR valve drew it's air (I contend that that is the source of the off-on throttle glitch-i-ness...). That spigot can be plugged with a 5/8" / 16mm vinyl chair leg foot, available at most Lowe's Depot or any hardware store.

Further: The air passage that the PAIR valve is sending air to/thru is a 7.4mm hole (about 5" long!) directly into the exhaust port - ideally, you'd want to plug that hole with a length of aluminum rod to prevent exhaust gases from traveling up the hole, and improve exhaust scavenging. Yet another project ...

Scott

 

Just to clarify. I reused the orange gaskets. I left them on the reed valve plates (that had the reed valves removed). I had to remove the reeds from my pair valves because the screw that holds them on protrudes just enough to prevent the blockoff plates from sealing.

It has worked great. No issues at all. I did have to go with shorter screws for the blockoff because they are thin. This was done at the same time I did the valve check and adjustment so the bike is torn down a bit more than need be just for the PAIR valve removal.

Note that the bike had 29k on it when I did the valve check and 6 intakes were tight. Check your valves!

 

I actually had to do this with the front unit. The aluminum plates are not a strong fit against the head, so some leaking occurred. I used the orange gaskets and had to remove the screw that holds the reed in place also.