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Discussion Starter #1
So has any one on here ever done an EGT test before and after removing / blocking the PAIR system? Also has anyone dyno'd the bike and ran and A/F ratio before and after blocking / removing the PAIR system?

Basically I'm asking this due to a discussion on Korider.com. We were reviewing some pictures of a GT650 motor that has been torn down with 10,000km on the motor. Looking through the exhaust port you can see the each valve stem hanging in the pic and a good portion of the port. The GT650 uses a system called an AIS, which is exactly the same as the PAIR system. Since the GT650 is just coming out this year with Fuel Injection and I have been told that the AIS uses a single vacuum solenoid with a sensor connected to the ECU and two hoses to each cylinder, assuming its similar to the PAIR system on the FI SV's. The carb'd GT's use a dual solenoid system and the AIS is only dropped into one exhaust port, not both.



In the pictures, the AIS goes into the right side port. So basically the left side port looks fine, kind of sooty but fine. The right side port has a white look to it, a bit cleaner but with an ashy residue in the port. So the AIS is injecting the air into the right port, burning the excess fuel in the pipe. Obviously the air is on that side so it's coming out leaner. But if the popping is being caused by the extra air causing a lean state, wouldn't that also raise the EGT. If my theory is right, this would obviously raise the EGT because its burning excess fuel as it exits the ports. So the white on the right port is obviously an indication of higher temps, since leaning out will cause white residue. So basically, if the EGT is raised on the right port more than the left port than the right side valve stem is going to be hotter which would cause it to fatigue faster than the left. Basically, if the material used to make that valve isn't quite as good as Suzuki's the valve will wear faster and eventually break.

So after I have bored you with my rambling, anyone know if the Suzuki's have been dyno tested. On the Hyosung forums everyone that has dyno'd their bikes and have the AIS removed / blocked have also rejetted. So this wouldn't give an accurate reading. Obviously with the AIS in the A/F ratio on a dyno will show a bit leaner than with the AIS not installed. Just trying to find reference since the concept behind both motors are so close to the same. And blown motors seem to keep pointing at faulty valves. Or in some cases, stupid dealers that don't know how to work on motorcycles and forget parts when putting them back together.

BTW Part of my theory is, you can remove the AIS all together as I read in a previous post on here about the PAIR. And as long as you rejet and get the A/F ratio tuned then you won't have anything to worry about reliability.
 

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When you dyno a bike it's always better to remove / blocking the PAIR system. This way you can set the air/fuel ratio correct. I have never tested the bike with the pair.

Here a expereance from a other member.
http://forum.svrider.com/showthread.php?t=95473&highlight=pair
Wait... this is the first time I've heard this. I thought the PAIR system only activates during partial throttle. Under WOT/acceleration shouldn't the PAIR Valve be closed?

I just had a Dyno run, but I never heard anything about disabling the PAIR system.
 

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Wait... this is the first time I've heard this. I thought the PAIR system only activates during partial throttle. Under WOT/acceleration shouldn't the PAIR Valve be closed?

I just had a Dyno run, but I never heard anything about disabling the PAIR system.
When you want to adjust the air/fuel ratio then you always need to disabling the pair system or else you get a false reading because the pair system inject fresh air to the exhaust.
When you make a custom map for a PCIII you also set the air/fuel ratio at partial throttle
(Throttle : 0% - 2% - 5% - 10% - 20% - 40% - 60% - 80% - 100%).
 

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Discussion Starter #5 (Edited)
That's just what I thought. I knew it would give a false reading. The thing that worries me most is the excess heat at the outlet valve over time. Just wish someone had one of those laser heat guns to point at the exhaust and find out the temp with the PAIR / AIS connected and with it disabled. I'm pretty sure its the cause of some reliability problems with the Hyo's.

Just got some answers from the owner of the pic above. That was the rear cylinder. The whole reason he pulled it apart was because he had a low water pressure reading out of that cylinder and he was loosing water. There was no exterior leaks in the gaskets or hoses so he was stumped. So he pulled it apart. So all the carbon buildup is probably due to water leaking into the cylinder. And the AIS is trying to do its job so the white carbon is burned radiator fluid.
 
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