Emission/ PAIR removal

[profile_deleted]

Ok... having searched around on the site a bit I am pretty sure that I know what's up with this, but before I go randomly removing things from my GS I thought I'd get a second (or third, or fourth) opinion.

The part(s) in question (see pic) are the PAIR system which I gather is a California emissions thing.... correct?  Not sure how my MD bike has the Cali emission but obviously bikes have a life of their own so I have to assume that this one started out on the other coast. 

Seems like removing it would not be a problem (I'm speaking mechanically... not philosophically or morally) by just capping it off with a blank (that I will make) and reusing the existing gasket. But before I do that can anyone confirm...

-I won't need to re-jet as a result (I don't mind doing it... just want to know going in so I can plan for it, rather than be surprised).

-Aside from the canister under the tank, there are no other extra parts (or complications) that will make this any more than a 1-2 hour job.

-Is there anything else associated with this system that can also be removed (there was some reference in another post to carbon filter attached to the airbox)?  I haven't had the tank off yet but don't see anything superfluous at first glance. 

Just taking this off to clean up the bike a bit (along with the oil cooler) as I'm starting my scrambler project on my most recent GS500.

Thanks.

B. 

p.s. As a result of the scrambler project I will have lots of parts available including some pristine bodywork (front fairing, side panels, rear cowl, seat).  I'll post something in "for sale" eventually but if you're interested, send me a PM.  Free as always...  just pay shipping.     


 

[Endopotential]

It's been a few years since I removed my PAIR system, so I may be completely wrong...

I think there's also a small rectangular air pump/reed valve box in the left front corner of the frame.

I don't think pair removal would necessitate jetting changes, as I can't imagine it steals that much vacuum from the system.
Though the PAIR system hoses can theoretically present another source of vacuum leak which apparently plagues all carbs.  So removing it is a good thing.

I seem to recall that it may contribute to popping from the exhaust during deceleration, but it's fun sound and doesn't hurt the engine.

[profile_deleted]

Thanks for the reply Endo.   Looks like removal will be next weekend's project.   I'll post the result, particularly if it's a fiasco...lol

[Bluesmudge]

FYI if you don't want to make the blockoff plates: you can buy them on eBay for the first gen Hayabusa and they fit. Its been awhile since I removed mine but I remember that much.

The PAIR system is not Cali specific (that is the charcoal canister and/or evap canister?) but all 2004+ bikes in the USA had the PAIR system.

There is additional emissions equipment attached to the carbs. All of which can be removed to simplify things.

[profile_deleted]

FYI if you don't want to make the blockoff plates: you can buy them on eBay for the first gen Hayabusa and they fit. Its been awhile since I removed mine but I remember that much.

The PAIR system is not Cali specific (that is the charcoal canister and/or evap canister?) but all 2004+ bikes in the USA had the PAIR system.

There is additional emissions equipment attached to the carbs. All of which can be removed to simplify things.

Oh man! Thank you. Already have them on the way. For 19 bucks they'll look better than what I will make and I will save the time. 

[Bluesmudge]

Plus the Hayabusa plates will come in a set of 4, so you can split the kit with another GStwinner or another GS project.

[profile_deleted]

Just a quick update for anyone that does this to their bike...

I installed the blockoff plates and removed the "canister" from under the front left of the tank and all the associated hardware and hoses.  There is a hose that goes from the canister to the airbox (lower left side) as well as a small hose that appears to run to the carbs (tried to confirm this as much as I could by poking around online since I did all this without removing the tank).

Started the bike up and it sputtered a bit and didn't like to be revved even on the stand.  Seemed that it was now getting too much air.  Checked my other GS (with no PAIR) and the bung on the airbox for the PAIR hose was blocked off so I made a stopper for the airbox on the newly "de-PAIRed" bike and pinched off the hose that was headed to the carbs and... 

Voila!  Back to running perfectly.

I suppose this makes sense as the both of these hoses were now drawing additional "new" air that would have otherwise just been recirculating... at least this is my theory.  Please correct me if I'm wrong, as I always like to learn but this seems pretty straightforward.

Since I'm planning on painting that tank as part of this build, I'll do something more permanent about the hose that goes to the carbs when I paint.  I'm pretty sure the PAIR system includes a hose with a T fitting that runs between the carbs which could simply be removed and replaced with a "regular" hose (or simply blocked off at the T).

Hope this info helps someone in the future!

B.