PAIR valve block

[katat58]

Hey everyone,

I just bought me an 06 Interceptor bout 3 weeks ago plus just joined the VFR web site. Been doing a lot of reading about the hesitation problems that seem to be prevalent on these bikes and some of the remedies. I did the PAIR valve block and the VTec transition does seem to be a bit smoother, still have hesitations tho at around 7 grand. Question is, will there be any ill effects to the engine in the long run with the PAIR valve blocked off? Just don't want to screw up my new ride!

[junktionfet]

The PAIR valve is misunderstood and it doesn't do what people think.

Underway and at operating temperature, the PAIR valve remains closed when the throttle is open... therefore the change you're feeling isn't due to your modification unless you're riding your bike aggressively before it has reached operating temperature.

There are no ill effects aside from increased cold engine emissions and perhaps a leaner mixture at idle when the engine is warmed up.

The PAIR valve remains open all the time when the engine is below operating temperature. The injection of fresh air into the exhaust stream oxidizes HC and CO emissions. That chemical reaction generates a lot of heat which brings the catalytic converter and O2 sensors to operating temperature faster.

When the engine has reached operating temperature, the PAIR valve is normally closed (no air injection), and only opens when the throttle is closed. This reduces HC and CO emissions while decelerating, and also offers a bump in the richness whilst idling--probably an effort to smooth out the idle. You can hear the PAIR valve close as soon as the throttle is opened--listen for a clunk or click as you slightly roll on the throttle from idle.

EDIT: BTW I have the same bike... Pearl White FTW :)

[katat58]

Thanx for the clarification junktionfet! The info really helps to understand the overall operation of the engine, hell, might as well unblock it and just wait till the bike gets warmed up before I get somewhat aggressive.

[Jessiah1]

I am also on the mission to clean the throttal up on this bike. Also get better rev response below 6k. Im thinking a filter and cans may go a long way after reading someones post on his BMC air filter and Remus cans. Sounded like it made a big difference. He mentioned something else that I cant quite remember....intake mod I think to a "flap"

[junktionfet]

A lot of people have tried adjusting the starter valves using the "staggered" procedure like the previous models called for. This softens the throttle response off-idle. The factory procedure for the 6th gen calls for adjusting the starter valves so that they are all the same.

Another tip to help throttle control is to make sure your throttle cable is adjusted properly. Too much free play in the hand grip can make the throttle seem more touchy than it is.

[Jessiah1]

(quote) Another tip to help throttle control is to make sure your throttle cable is adjusted properly. Too much free play in the hand grip can make the throttle seem more touchy than it is.[/quote]

I was thinking of checking that out today. Is the adjustment for that near the grip, or am I taking a fairing off?

Heres the link to that Remus BMC flapper door mod. Remus exhaust + BMC filter = holy SHI....!

Is that flapper mod just letting more air in? Which would mean you need more fuel, right?

[junktionfet]

Originally Posted by Jessiah1

I was thinking of checking that out today. Is the adjustment for that near the grip, or am I taking a fairing off?

Heres the link to that Remus BMC flapper door mod. Remus exhaust + BMC filter = holy SHI....!

Is that flapper mod just letting more air in? Which would mean you need more fuel, right?

Yeah the throttle adjustment is an 8mm and 10mm nut on the throttle cable near the grip. Break the 10mm locknut loose then turn the 8mm nut to adjust. Turning it to expose more thread tightens the cable.

Regarding the flapper door on the airbox--At low RPM, the flapper door is supposed to be closed. This ensures slightly higher air velocity into the airbox which is helps boost torque by a marginal amount as well as increase throttle response (which might not be a good thing). Think of it as a miniature faux-ram-air effect.

At higher RPM, the flapper door opens because the engine is actually able to use the potentially higher volume of air entering the airbox. Plus, the extra noise generated is kind of nice. One thing to keep in mind is that the flapper door is not a "throttle valve"--it does not limit the amount of air entering the engine at low RPM... if anything it helps boost the amount of air, if only by a small amount..

If memory serves, the flapper door is supposed to open at somewhere just over 5000 RPM.

Disabling the valve would probably result in a reduction of power/torque at low RPM on a dyno, but it might tame the throttle response at low RPM? I don't know...