Pair Valve Mod and O2 sensor

[twiin640_imp]

I've found all the 411 I need on the pair valve mod for popping exhaust. Easy enuf to do and appears to do the trick. I ordered the sp tadao power box short slip on muffler system. If for some reason I notice pops more than my liking on decel, I'll do the pvm.

So here are some questions:

1. After the pair valve mod, does the O2 sensor now sense a decrease of O2 and modify the engine air/fuel mixture?

2. Has anyone found any negatives to doing the pvm? ie: mpg decrease, power decrease, long term effects, etc.

3. Besides the reduction of "popping" exhaust, has anyone found positives to doing the pvm? increased mpg, power, etc.

As always, thanks in advance for any info.

[Gumby 1100_imp]

I've found all the 411 I need on the pair valve mod for popping exhaust. Easy enuf to do and appears to do the trick. I ordered the sp tadao power box short slip on muffler system. If for some reason I notice pops more than my liking on decel, I'll do the pvm.

So here are some questions:

1. After the pair valve mod, does the O2 sensor now sense a decrease of O2 and modify the engine air/fuel mixture?

2. Has anyone found any negatives to doing the pvm? ie: mpg decrease, power decrease, long term effects, etc.

3. Besides the reduction of "popping" exhaust, has anyone found positives to doing the pvm? increased mpg, power, etc.

As always, thanks in advance for any info.

The simple answer is NO to all your questions, although, I doubt that anyone has done a scientific test of questions 1 or 3.

Regarding 2: The only potential negative to the PAIR valve mod depends on how you accomplished it. There is the possibility for some condensation to form in any of the remaining PAIR air lines, but this is generally not a problem on most bikes. Some have also noticed an increase in exhaust smell since the unburned gasses that the PAIR system was designed to burn off are now vented to atmosphere.

Regarding 3: The exhaust may now run slightly cooler, but again, no-one to my knowledge has really measured or verified this. Some have claimed the engine runs smoother, but this is likely just the power of suggestion since the pair valve operation takes place post combustion and should in no way affect how the engine runs.

[twiin640_imp]

Another question. I've seen this done on other bikes. Has anyone found and used pair valve block off plates on the cb1100?

[Gumby 1100_imp]

Another question. I've seen this done on other bikes. Has anyone found and used pair valve block off plates on the cb1100?

To date, I don't believe that anyone makes such plates for the CB1100. I've had several bikes in the past for which I purchased the plates such as for my RoadStar 1700, VTX 1800 and others.

With the CB1100 you're presently limited to blocking off the hole in the air box that feeds the PAIR System, any of the hoses leading to or from the PAIR Valve itself and/or to the two lines leading directly to the heads.