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what’s up everyone? I hope all is well. The reason why am making this post is to ask about the pair valve block off. I initially heard about it when I was going to take my motorcycle to get dyno tuned. The Mechanic mentioned that you don’t need to get block off plates, and that they use whatever ever they have lying around in the shop to throw in there. That is not something that I want to end up doing. I ended up ordering block off plates from grave. I was wondering if anybody has instructions on how to install them. The directions that they sent me are very generic. Also, does anybody have any ideas on how the pair valve system works? I know a little bit, but would like to hear everybody else’s opinions. Thank you in advance for your responses.
 

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Simply disconnecting the solenoid accomplishes the same thing for free, doesn't require tools, and can be done and undone in seconds.

The pair system is an air injection system that helps to lower emissions by burning un-burnt fuel in the exhaust. There is an electrical solenoid valve that the ECM opens to let fresh air in when conditions are correct. It draws that air from the airbox and that is the hose you always hear people talking about blocking off. Blocking that hose does the same thing as installing block off plates. Unplugging the solenoid does the same thing as blocking off the hose or installing plates. That solenoid valve is closed when no power is applied. No air is getting by it with it unplugged. It will not cause the check engine light to come on since it's not a monitored output.

Block-off plates are best used when you are looking to de-clutter the system by removing the pair system entirely and never put it back on.

If all you need to do is disable it for tuning, unplug the solenoid. When you are done tuning, plug it back in, easy! The pair will not affect running and causes the bike to pollute more so there's no advantage to leaving is disabled, but all that extra air in the exhaust does mess with the tuner's exhaust sniffer. If you want to install the plates, you can remove the rest of the pair hoses and solenoid for more room under there. The hose going to the airbox will need to be left in place and blocked off or removed and a plug installed in the airbox in it's place. If you don't do one of those, you will be sucking unfiltered air into the engine.

Some say it can lessen some popping from the exhaust by leaving it disabled, but I've never been able to tell a difference myself. I don't know if it's the loud-ass exhaust I have or if it's a placebo effect people get from it, I just can't tell a difference.
 
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Pulled all the PAIR plumbing & solenoid off my Hornet a few years back.
Tidied up the top of the engine. Used blanking plates, and took reeds out
ISTR dropped about third of a Kg in weight.
Stopped popping on over run & decel...dead.
No increase in performance though.
Boooo!
 

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Duluth, if I'm running autotune, can I keep this solenoid disconnected, or should I do the block off, either the plates or the hose? I just started installing the pcv and autotune. I just read about this. I'm kinda flying by the seat of my pants, and want to make sure I'm doing everything necessary. Running yoshi r77, if that matters. Sorry, I know this is an old post. I'm a noob, be easy. Thanks in advance.
 

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Welcome to the forum, Hambone.

Unplugging the solenoid does the same thing as blocking off the hose or installing plates.
It will not cause the check engine light to come on
Block-off plates = air can't get in
Plugged hose = air can't get in
Unplugged solenoid = air can't get in

It's all the same to the engine/computer/PCV.
 

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You are welcome. No excuse needed, though. Happy to help. :thumbup
 

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So... I ordered the plates anyway, just to clean it up a little. They weren't expensive. Well, in the process of trying to remove the stock plates, very first bolt broke. I know they have yellow lock tight on them, but it shouldnt have broke, right? Then next one is super tight too. I've extracted broken bolts before, but this one is going to be a PITA. There's too much stuff around to put any heat to it. Anybody else have this happen? I don't want to try the other ones now, but I'm kinda forced to. Open to any suggestions.
 

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Shit. Just thought of something. Do I need to remove valve cover to remove the pair valves? They are accessible without, but now I'm wondering if they're thru bolted and that's why it broke. I feel so dumb right now.
 

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Thanks, Tifa. I wouldnt think so either. Every single one is super tight. I'm working them in and out a little at a time, but they dont feel good. I fell like they're all gonna break. This should be a simple job. That yellow loctite is acting like red. This is ridiculous. Talk about ruining the weekend.
 

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The bolts do not go through.

Locktite melts. Use some heat.
 

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Yeah I did, but I was afraid to use heat while it was on the bike with everything under there. So, I removed valve cover, and got the other 3 out. Thanks for the input Deluth. I'm new to the forum stuff, so I dont know if I'm posting too much. Now to get the broken one out.
 

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I made a cap by robbing a connector from an old wire harness or a part, can't remember which. I think it might have been an old A/T shift solenoid connector that I used.

You can also saw the connector off of your PAIR solenoid and use that if you are scrapping the system anyways.
 

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I know this thread is old, but as I was looking into this and trying to understand it all, I came across a video which stated that the PAIR valve is normally open, so unplugging it is not the same as using block off plates or capping the hose. He gives a demo of that on a Busa here:
 

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guynichols, DEluth has not been on this site since April, so it might be we've lost his comments, but I would trust what he said. he's a Honda tech.... and buddy on your video is talking about a Suzuki, not a CB... I don't know for sure, but...
 
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