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Discussion Starter · #1 ·
Hi All:

I understand the PAIR system injects air into the exhaust for emission reasons and how to eliminate that (this is on a bike used solely for track days and race events) but I don't really understand the Air Switching Valve's role. Can someone educate me? Did all models have this valve? I'd like to remove it if it can be done without harming the engine.

thanks
 

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It can certainly be removed. The valve is just what decides when air gets injected from the airbox to the exhaust stream. It can close or open based on what the ECU signals it to do. My understanding is that the valve is not a pump or anything of the like. Air is pulled from the airbox through the reed valves when there is negative pressure in the exhaust stream I believe. The switching valve just has the power to say 'no' to that happening.

You have a few options here to remove or disable the PAIR system:
  • Plug the airbox tube leading to the valve. This will stop the system from doing the air injection, and you don't have to remove any more parts, and you won't get an FI light.
  • Block-off plate(s) and remove the switching valve entirely, and either get an ECU flash or an eliminator to remove the FI light from having the valve disconnected.
  • Or some mix of the previous two items.

If it's a track bike like you said, might as well just get the block off plate, remove the valve and plumbing, and get an ECU flash and fuel tune. That's the usual approach for track junkies if you're gonna do it. I am also a track day enthusiast, and honestly I have left the engine, exhaust, air filter, all that stuff stock. I am not racing, so tenths don't matter to me, and it runs pretty smoothly stock. That said though, after getting my GSX-R dyno tuned and ECU flashed, I am so impressed that I may do it to my Ninja 300, and just do the PAIR delete and block off plate as well.

Anyhow, hope this helps.

-Mike
 

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I think if you remove the valve, you get an error code in the dashboard.
When I did the PAIR mod, I pull out the hoses, put the block off plate in the valves cover, a plastic cap in the air box and kept the valve in its place and plugged to avoid the error code.
I don't remember if it was an error code or an amber engine light.
 

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Discussion Starter · #4 ·
Thanks guys. I'm removing mine to reduce complexity and save a bit of weight. The engine spends its life at WFO anyway. I'll get a bypass plug from Kawasaki Brad. The engine is out as I went to backcut tranny gears (always jumping out of gear, even with the upgraded shifter "star" mod) and I'm also going to re-ring it and install hotter cams along with a decatted exhaust pipe (it has a slip-on). It already had a PC5 and I'm installing an Autotune module to try to zero in on best A/F ratio.
 

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Hey Frank does the heavier shift detent spring change the way the bike feels when shifting at all? Or does it just make sure that the bike clicks into the next gear when you shift? My bike has done the magic downshift on me a couple of times, not enough to bother me too much but while I have it apart this winter I thought I might add the heavier spring.
 

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Discussion Starter · #6 ·
I didn't really notice any difference in shifting feel when I installed mine. It helped the random downshifting a bit but at the end of the season it was messing up about once per lap, usually from 5th gear. It's fairly easy to do, just have to remove the clutch basket to access everything.
 

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Man, this popping out of gear talk is kinda spooky. I've never ever had a bike pop out of gear. I've had old cars pop out of gear, but man on a sequential transmission on a bike that sounds awful. I've false neutral'd before for sure, but never pop a gear.

In my understanding, if you're popping in/out of gears, no amount of quickshifters or other parts will truly fix the issue, and that you absolutely have to go in and replace the gears, shift dogs, shift forks, shifting drum, or whatever is causing the issue.

And I believe on the 300, repairing those components means splitting the case halves unfortunately.

Did either of you guys have a left-side crash and land on the shifter causing gear issues? I've seen that before where someone crashes on the left side, and it just ruins the transmission, never shifts right again because it was forced a gear in the crash. I actually crashed on my 300 on the left side recently, and I am convinced the folding shift peg and rearset saved my transmission.

-Mike
 

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it has only happened to me a couple of times and I think due to me “limp wristing” the shifter. I came across the spring on Spears website and was wondering if it made the bike feel and shift better. In my case I don’t think it is worth installing as it hasnt been an issue but I think for many (like Frank) it becomes a real problem which is why places like Spears Racing etc. have found/developed solutions.
Im not adding a quick shifter to help/fix any problem. I just want to try a quick shifter. Figure while I have the bike apart to check my valves, I may as well toss one under there.:geek:
 

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Sometimes, I get both kick backs and false neutrals. Always at the track. Don't remember having them on the street.
Kick backs always happen when upshifting and when I don't shift all the way. I feel I'm too gentle with the lever. The higher gear stays for a bit, then it kicks back down.
I get false neutrals when downshifting. If I let my body slide forward on the seat in the braking, my foot can't pull the lever up enough (gpshift mode) and I get a false neutral.

Also, it always happens later in the day when I'm already tired.
 

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Discussion Starter · #12 ·
Man, this popping out of gear talk is kinda spooky. I've never ever had a bike pop out of gear. I've had old cars pop out of gear, but man on a sequential transmission on a bike that sounds awful. I've false neutral'd before for sure, but never pop a gear.

In my understanding, if you're popping in/out of gears, no amount of quickshifters or other parts will truly fix the issue, and that you absolutely have to go in and replace the gears, shift dogs, shift forks, shifting drum, or whatever is causing the issue.

And I believe on the 300, repairing those components means splitting the case halves unfortunately.

Did either of you guys have a left-side crash and land on the shifter causing gear issues? I've seen that before where someone crashes on the left side, and it just ruins the transmission, never shifts right again because it was forced a gear in the crash. I actually crashed on my 300 on the left side recently, and I am convinced the folding shift peg and rearset saved my transmission.

-Mike
I think what happens is that the edges of the dogs get rounded off so it's easy to pop out of gear. The shifter-star upgrade uses a stronger spring to try to hold the shift forks in position but it's hard to overcome the pressure of the dogs being forced out. My bike has never crashed on the left side (that I know of and there's no evidence that it has). I bought the backcut gears from Spears for logistical reasons; I usually get trannies backcut by R&D Motor Sports in Florida. I have had four other bikes with the backcut done and none of them have ever had shifting issues.

It's easy to not shift properly when you're tired, or in an awkward position on the bike or something but that's not what this was. About one second after shifting into 5th it would drop back to 4th. Of course the engine immediately overrevs and can't make power anyway. This got progressively worse over the past 3 years and at the end of this season was sometimes happening twice/lap (the only two places I was using 5th gear).

And yes you have to split the cases. It's not that bad really: the only potential sticking point for me was that the manual says to pull the alternator rotor (to access an oil pipe that bridges the case halves) but you can wiggle it out once you remove a holding screw and start to split the case halves.
 

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Interesting. Yeah I would agree on the shift dog wear, it's just how it goes after a while. I feel like that is a self-worsening issue as well. If you don't have it, it will stay good, but if you develop that issue, it can easily get worse. I think my 6th gear dogs are slightly worn, I sometimes get a false neutral 5 to 6 once in a blue moon.

If I was having shifting problems every lap, or even every track day, I would probably get in there long before it got that bad lol. I would just be so frustrated.

If you tear into it, share your findings! Would be neat to see what's going on in your trans.

-Mike
 
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