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I did the flapper mod. It was pretty easy, took about an hour. As far as the PAIR mod, that's on the back burner for me. I don't race the bike, street only, and as long as the PAIR doesn't effect performance in a measurable amount, I'm going to just leave it on. I understand it helps clean up the exhaust. Since I live in a pretty densely populated area, and Sacramento is #5 for worst ozone pollution in US, I have no problem leaving it on. Let it do it's job, while I modify, sprockets, exhaust cans, tires, and pcIII to get that extra performance.

I'm going on a tangent for a second, cause I think it bears mentioning. My son Kenny (now 25) was diagnosed w/ chronic asthma at age 6 months. His life options are obviously limited because he can't breathe normally. My opinion about the PAIR mod is that one should really consider the necessity for their specific case. I don't think it should be a 'go to' mod. For some applications it IS appropriate. But for a street only bike? Differing opinions welcome...
 

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Since I ranted a little in the last post, I thought it appropriate to pass this along. Probably some have seen it already, but I just came across it and thought it was relevant...

Should I do the PAIR mod? Some quotes from our wise Yoda figure (WSTAAB):
The PAIR(exhaust port air injection)system causes some of the popping noises in the exhaust system and adds extra heat in the primary headers. It also effect the A/F ratio readings taken with probes in the exhaust pipes. Some aftermarket exhaust mfg. recommend disconnecting the system with their FULL exhaust systems to reduce the heat generated in the thin wall SS tubing most are made of.
>>and also:<<
Because the PAIR system is passive (it uses negative pressure in the exhaust port to suckfresh air in), I don't believe it has a direct effect on horsepower. The main benefit is the ability to more accurately measure the engines true A/F ratio in the header. A side effect would be less heat from the front header radiating to the oil cooler and radiators. Less heat from the rear header could have a positive effect on rear shock damping. There is a small weight loss from removing the entire system.
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Look in the manual..I believe there are some lines that will need blocked off...my manual is with my bike:rolleyes:
 

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For the PAIR system, if you bought the PAIR block off plates, you eliminate the hose fittings coming from each valve cover.
The two hoses go to the PAIR solenoid, and from there a single hose to the airbox fitting.
So, you should have the PAIR solenoid and three hoses once removed.
The only remaining issue is to plug or cap off the unused fitting on the airbox.
 

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Can I remove it and how? And what impact will it have on the bike?
Basically, instead of venting to the air outside, the fuel tank vent hose is instead routed to the Evap canister to store the fuel vapors.
When the engine is started, the Evap purge control solenoid is opened, and the fuel vapors are routed to the throttle bodies and into the engine.
Outside air is allowed to flow through the Evap canister to assist purging of fuel vapors.

As in this diagram from the service manual shows.


So to remove, it appears you disconnect the Evap purge control solenoid on the throttlebody, remove and plug the fittings where the Evap canister hoses went, then pull the fuel tank to Evap canister hose and allow the fuel tank to now vent to outside air.



 

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Discussion Starter #9
Thanks Sub, any idea on what impact that will have on the performance of the motorcycle? Maybe hard starting?
 

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Probably no impact at all on performance, except for weight loss.
All it does is store and forward fuel vapors to the engine.
Be sure and block the hoses to the throttle bodies to prevent vacuum leaks, and allow that tank to vent freely.
If not, the fuel pump will collapse that tank into a crumpled lump.

Of course in California, if they find out what you did, they'll probably label you an enviro-terrorist and boil you in (free-range organic non-carcinogenic) canola oil.
You'll get two Karma demerits and not be allowed in the drum-circle on the beach.
So be warned!!!
 

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Good & bad

Fuel vapors. Some of those alcohols used as fuel additives are also acting as octane boosters, and some are more volatile than others. This is what this rumor about premium gas turning to regular after a while is based on.
These alcohols also have a different optimal A/F ratio and their addition makes you engine run a little leaner.
So, the more ethanol and methanol your gas has and the warmer the tank is/gets the more vapor you have. In the old days it used to be just a tube coming from the tank or cup and went straight into the neck of the triple clamp. This is wasted fuel that evaporates. But gas itself releases vapor and more of it with heat.
The valve in this circuit closes venting down when the bike is turned off and once started it releases this pressure back into the intake.
So depending on your use and conditions of where bike is stored etc and the fuel you use you may decide for or against it.
If you have been keeping your bike in a tiny storage space within the house/garage it may smell up with fumes after you remove this gadget.
 
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