Pair Valve Block off with PCIII USB????

jblackbird2000 · 11-07-2006, 12:39 PM

So I took advantage of the PCIII GB, and hopefully will get around to installing this weekend.

However, I'm a bit confused about the Pair Valve block off mod that some here have done. I've searched here and .com and haven't found much on the issue.

Is it necessary? What will be my gains/losses if I do it or don't do it. From what I've gathered, it's easier to get the tank on and off, but I'm wondering if I will see any performance enhancements with the PCIII.

Any insight on what these these pair valves do and how blocking them will affect my ride would be greatly appreciated.

Oh - and if it matters, I'm running Mig slip ons, like my avatar shows

Thanks guys!

Jay

Warchild · 11-07-2006, 12:47 PM

There is no power gain or loss when using the PAIR Block-off plates. For the most part, it "cleans-up" the valve cover area and makes accessing the spark plugs considerably easier.

Plus... the Block-Off Plates are very cool.

AFAIK, several XX owners have the PAIR Block-Off plates and run the PC-IIIusb with no problems, so I think this is a non-issue for you.

Still, I'd like to hear from those running this combination to ensure this is the case...

RedJ · 11-07-2006, 2:04 PM

Quote:

Originally Posted by jblackbird2000

Is it necessary?

It is not necessary.

Quote:

Originally Posted by jblackbird2000

What will be my gains/losses if I do it or don't do it. From what I've gathered, it's easier to get the tank on and off, but I'm wondering if I will see any performance enhancements with the PCIII.

The main benefit that removing the PAIR system is that you clean up the top end of the bike's engine for servicing, and that you will ensure that the exhaust gases in the exhaust pipe (as seen by a wideband oxygen meter) are consistent to those which are in the combustion chamber.

The tank is no easier or more difficult to remove. Same with the airbox.

The plugs are easier to get to, when the bike is modified. Same with removing the valve cover for valve inspections and adjustments. In my opinion, this is the biggest reason to remove the PAIR system.

Quote:

Originally Posted by jblackbird2000

Any insight on what these these pair valves do and how blocking them will affect my ride would be greatly appreciated.

The stock PAIR system (P)ulses (AIR) into the exhaust stream from the air filter housing. During use, the engine is pumping hot, inert gases with (possibly) surplus fuel into the exhaust. Without a suitable gas to burn, the fuel makes it's way out the exhaust tip, unburned.

This, according to the EPA, is bad.

So, what Honda have done, like many others, is allow fresh clean air to pass thru the valve cover and cylinder head, controlled by a reed valve which opens on exhaust valve closing, into the exhaust port, to mix with the exhaust gas and surplus fuel and burn (since the exhaust gas is hot) the remaining fuel.

This creates:

1. Less CO in the exhaust pipe.
2. Exhaust pipe AFR (air/fuel ratio) is not consistent with the combustion chamber.

So, no performance benefit, other than you can tune the engine more accurately since there is less discrepancy between the exhaust system and combustion chamber gases.

And the performance benefit you get when you can change your sparkplugs faster.

There are instances where the PAIR blockoff kit has reduced the number of pops in the exhaust when decelerating off the throttle, but this is not the main reason to do it.

J.

Para045 · 11-07-2006, 2:10 PM

So i am guessing that other than cleaning up the top of the motor there are no advantages whatsoever with a carb bike - would that be correct

jblackbird2000 · 11-07-2006, 2:22 PM

Most excellent explainations gentlemen, thank you very much. That certinally straightened me out.

I think I am going to block these off.

Jeremy- Wasn't it you that was selling some of these block off plates? If so, do you have any left?

Without the plates, couldn't I simply attach both ports with a hose and a couple of hose clamps to effectively block them?

Jay

RedJ · 11-07-2006, 2:26 PM

All the same reasons apply to the carbureted engine as do the fuel injected engine.

Each will benefit from more accurate AFR monitoring during tuning, and each will be easier to service.

Warchild · 11-07-2006, 2:27 PM

Couple photos for those who haven't seen these before....

1st photo: Stock reed cover shown installed on right side, no cover on left side. Kit covers in foreground.

2nd photo: Kit covers installed.

3rd photo: Airbox nipple cover and zip-tie.

RedJ · 11-07-2006, 2:29 PM

I have one kit remaining, it is a blemished kit which has some flaws (small) in the finish. The kit is fully functional, elsewise, I'd not sell it.

It's yours for $35 shipped.

The system can be defeated by plugging the hose nipples on the reed covers, but my kit is a cleaner way to defeat the system and allows you the most room for servicing.

If there is enough interest, I will produce more kits.

jblackbird2000 · 11-07-2006, 2:41 PM

Quote:

Originally Posted by RedJ

It's yours for $35 shipped.

You have a PM sir!

WestOzBird · 11-08-2006, 9:06 AM

Haven't said it to you personally RedJ, but thanks for the great product. Well haven't got it yet but Bluear is sendin it to me as we speak.

When I finally get my PCIII from the group buy. The PCIII, Yoshi slip ons and the pair kit are all headin to the dyno for a run. Will post pics ( when I work out how to do it) and let you all know how it went.

Warchild · 11-08-2006, 10:02 AM

Quote:

Originally Posted by WestOzBird

When I finally get my PCIII from the group buy. The PCIII, Yoshi slip ons and the pair kit are all headin to the dyno for a run.

Not that I expect a massive difference from prior model years, still, I'm almighty curious to see the dyno number before and after these mods.

While the differences would like be fairly significant if you had a full Yosh system vice the Yosh slip-ons only, I'm mostly interested in the numbers produced by a non-California, 2006 model year Blackbird.

*sigh*.... dayumn... a 2006 model year Blackbird..... you lucky Aussie bastards....

RedJ · 11-08-2006, 10:17 AM

No joke, Dale.

WestOz, hope you do well with the kit. I think you're the furthest customer from me...

WestOzBird · 11-09-2006, 6:12 AM

Quote:

you lucky Aussie bastards

I resemble that remark thank you very much.

Thanks Red, it's justa 4000km side step from Bluear

Para045 · 02-24-2007, 1:48 AM

Quote:

Originally Posted by Warchild

Couple photos for those who haven't seen these before....

1st photo: Stock reed cover shown installed on right side, no cover on left side. Kit covers in foreground.

2nd photo: Kit covers installed.

3rd photo: Airbox nipple cover and zip-tie.

It may sound like a silly question but do all the XX's sold that you know of have the PAIR valves, it is just that I did a sparkplug change on my 98 XX the other day and on the cam cover where Pair valves are supposed to be like on the first pic all I seem to have is the raised casting, there is no reed valves and after lots of looking and poking around with a screwdriver there does not seem to be any holes in the camcover for air etc to pass through and there are no hoses going to the airbox

. Could it be that the non US Birds did not have PAIR valves

the manual seems to indicate that there should be PAIR valves but it is a US manual so maybe early Oz birds were exempt

Partsguy · 02-24-2007, 8:26 AM

All the ones I know of.

tbonelynch · 05-05-2007, 2:57 AM

This may be true. My wife's 2000 Suzuki Maruader 800 has a PAIR valve that looks like an air cleaner on a v-twin. The non-us model have the same fake "air cleaner" but it is used as a tool box, with no PAIR valve installed. This is stated in the maint manual.

Para045 · 05-05-2007, 7:47 AM

While I had the panels and seat etc off the other day I decided to go all the way and take some pics, they are not the greatest as the camera is an old one and it was very awkward getting it in there without too much flash but you should be able to get the picture (no pun intended

)

AlBlack · 05-07-2007, 6:32 PM

I have a copy of the Honda dealer workshop manual and it says the pair valve was only fitted to US models....

silvertippr2001 · 05-12-2007, 12:17 AM

Quote:

Originally Posted by Warchild

Not that I expect a massive difference from prior model years, still, I'm almighty curious to see the dyno number before and after these mods.

While the differences would like be fairly significant if you had a full Yosh system vice the Yosh slip-ons only, I'm mostly interested in the numbers produced by a non-California, 2006 model year Blackbird.

*sigh*.... dayumn... a 2006 model year Blackbird..... you lucky Aussie bastards....

to tell you guys the truth I do not now if it was blocking the pair valve or what, but I have a 99 bird with a full yoshi system and a pc 3 usb, when we dyno tuned her she gave 144.83 hp. maybe it could be from were I'm ,but I've not seen numbers like that on a stock bird before, correct me if I'm wrong .

slyxdevil · 05-22-2007, 2:36 PM

check out 98 carbed bike post this guy v 8 eds is telling me i should dyno at 187rear wheel horse power with a full exhaust system muzzy and factory jet kit with k&n air filter? think this is possible?

OZDave · 05-23-2007, 9:57 AM

Quote:

Originally Posted by slyxdevil

....187rear wheel horse power with a full exhaust system muzzy and factory jet kit with k&n air filter? think this is possible?

NO!

Para045 · 05-23-2007, 10:21 AM

Quote:

Originally Posted by OZDave

NO!

Tell him he's dreamin!

slyxdevil · 05-23-2007, 11:10 AM

i didnt say it someone else did i said same thing maybe at crank ..lol

r2t2 · 05-23-2007, 11:25 AM

Quote:

Originally Posted by Para045

While I had the panels and seat etc off the other day I decided to go all the way and take some pics, they are not the greatest as the camera is an old one and it was very awkward getting it in there without too much flash but you sh