P.A.I.R elimination? By blueboy5000 (Read 2,045 times)

[blueboy5000]

After chasing a random backfire on my 2011 Baccio 150t, I was finally able to discern with 100% accuracy that my P.A.I.R vacuum solenoid is wasted. It stays fully open at all times, causing a loud backfire on deceleration. For two weeks I messed with two different 24mm carbs and various jets, only to get this backfire no matter what I did.I chased around every hose and sealing point with propane double, tripple even quadruple checking for and possible vacuum leaks that could cause such a "lean" popping backfire. Since I found nothing with either carb and still had the backfire, I finally decided to check out the P.A.I.R. solenoid.

With the solenoid disconnected from vacuum, problem solved! No pop.

So I want this pseudo- emissions air pumping system gone. I suspect it never really worked right. I also suspect the P.A.I.R does little to nothing beneficial to the engine ( even possible that it is potentially hazardous since it causes backfiring).

My question is what to do with the valve cover? Can I block the reed valve? Is there a way to do that? Or should I get a standard non-pair valve cover?

I easily fabbed a plate for the exhaust passage, I'm not sure what to do with the valve cover.

Thought?

[blueboy5000]

Nvm. Guess it all just pops of Np.

Installed the block-off plate and capped the vacuum port the PAIR was attached to. Removed and discarded the entire PAIR system.

Readjusted the carb and what a difference! No popping! No backfire!

I see no benefit to this system at all in a set up that has no catalytic converter. All it does is force air into the exhaust, facilitating possible catastrophic damage should it malfunction and remain in the "open " position.

If your local laws permit it, remove and toss this garbage at once!

[blueboy5000]

I believe this system to be an attempt to "cheat" sniffers by forcing air into the exhaust.

[JR]

Sorry I didn't see this earlier Blueboy and yes many people have blocked the reed vavle with a cover, even made their own.

From what I've read if the system is functioning properly it causes no performance issues with the engine. But you've already shown what happens when they do malfuntion.

JR

[blueboy5000]

Yep. If it ain't broke, as the saying goes.

I always wondered what the PAIR was for. And after removing mine, then taking a 30 mile ride with two riders from my club (Grey Market Raiders, shameless promotion ) to my sister's house to uncrate and PDI her new Jonway, I finally figured it out:

The PAIR is the equivalent of an AIR injection system on a car. It supplies fresh air directly to the exhaust port so enough air is present to active a catalytic converter. Her bike has full California emmisions. It has a cat in the muffler, an EGR, a fuel vapor reclamation canister and of course a PAIR.

My Baccio only had a PAIR, no cat, egr or canister. The only logical reason I could see for this is to "cheat" a gaschromatigraph. Buy having air pumped into my exhaust, it would test as being cleaner than it really is.

But sans egr and catalytic converter, this is a ticking time bomb of a system. With solely a PAIR, it's fine till the solenoid frags, but if does you will now have exhaust ignition, which can potentially ruin your inner engine (most notably valves or piston!).

So in conclusion, I do not advocate removing the PAIR if you also have an EGR and a cat. But if all you have is a PAIR, then toss it (if local laws permit) and save yourself the risk of possible bricked engine.