We just got off the phone with Kawasaki HQ, and it’s official: the 2011 Kawasaki ZX-10R will inadvertently get a power decrease when it comes to the United States because of the EPA’s regulation of noise pollution, confirming earlier rumors from this week. The issue surrounds the EPA’s new methodology for measuring exhaust noise levels, which now involves taking the measurement at a percentage of the total rev range, instead of a specific rpm value.

The result is that the 2011 Kawasaki ZX-10R passes the Euro III standards, but fails the EPA standards in its unadulterated form. To come into compliance with the EPA’s Noise Control Act, Kawasaki has lowered the rev-limit on the 2011 Kawasaki ZX-10R by 750 rpm in order to meet the new criteria. The byproduct of lowering the rev-limiter will reduce the new ZX-10R’s maximum power output, but Kawasaki isn’t saying by how much.

Kawasaki says its the redline for American 2011 Kawasaki ZX-10R’s will be 13,750 rpm, and sources outside of Kawasaki say the drop in peak power could be by as much as 10hp at the crank. Kawasaki insists that nothing is mechanically different from the European model and the American model (the EU model does have an ignition disabler, but that’s not really relevant), with the differences between the two bikes residing in their computer software. While they won’t specifically state how they are changing the bike’s ECU firmware, we can assume that some sort of software rev-limiter is being employed to bring down the maximum rpm figure.

This news will probably disappoint spec-sheet racers, but the practicality is that riders looking for the 197 crank horsepower from the ZX-10R won’t have to look far as modifications and aftermarket products are sure to hit the streets immediately after the 2011 Kawasaki ZX-10R’s debut here in the USA.

  • Andrew

    This story bothers me for two reasons. First, the fact that Kawasaki can get around the noise regulations by lowering the maximum RPM by 750 shows how the formula for determining the vehicle noise isn’t very good. Unless the EPA is taking the measurement at 94.8% or greater of the max revs then this bike will still be able to hit the level that was previously ruled too loud and will likely be ridden at those revs just as often. In effect, this change makes the bike no quieter (not that I’m saying that is a bad thing). Second, assuming that the engine has been changed in no way other than lowering the limiter, cutting out the last 750 RPM will change the riding experience in no way unless the rider plans to operate the motor beyond 13750RPM. (Sure that might matter on the track, but I’m sure there will be a mod that will allow the additional revs since a lot of things are done to a track bike that aren’t street legal). Additionally, the loss of 10hp is a worst case scenario and would only happen if the peak hp was realized at 14500. Basically the only thing this affects is how this bike’s specs rank against its competitors, so Kawasaki should be more concerned than us.

  • AB

    I completely agree with Andew. Well said. For the track, none of this would probably matter as I’m sure aftermarket parts and engine maps would nullify this change. For the street, the noise impact has not been lessened at all, the sound levels will still be reached at the RPM levels where the test had failed prior to lower the Max Revs.

  • MikeD

    Well, that was short lived. Way to go EPA…AND Kawasaki for not seen this one coming(they kind of deserve it).

    Like the article said, there will be ways around this minor setback and beyond soon enough to restore w/e is been lost and gain some on the process.

    This reminds me of something i read today about their own new Ultra 300X JetSki. Dealers that rode it at Lake Havassu are going off the hook saying how great it is (Holeshot, Acceleration,u name it) but someone pointed out it was Pre-Production Units most probably not restricted=The Old Trick of Bait and Switch [SHOW THEM TURKEY BUT FEED THEM CROW]…suposedly making 70+mph (US CoastGuard have all manufacturers limited to 65Mph)… Kinda looks the same here.
    The Nany State doing its thing, screwing the Lamb each and everytime it can.

  • ML

    Lets complain about power 99.9% of us will never be able to fully use. ECU reflash/Power commander anyone?

    Get over it…

  • 750 RPM? Really? Get over it! It’s not going to change peak power on this bike at all, chances are that peak power is going to be below the redline anyway!

    All this hype for nothing!


  • MikeD

    ML & Hamza: Is not about that at all, is all about “MINE IS BIGGER THAN YOURS” specially on the good old U.S of A and the SIDE EFFECTS of OVERPROMESSING and UNDER DELIVERING. Allow me…

    Squid#1 with some money and no brains at all: Yo, that Kawi that just came out got mad power, 197hp YO!
    Squid#2:True da, but not anymore, it got its Balls cut YO! Now it “ONLY makes 190″…Less than the BImmer…(or w/e happened to be fastest at said time)
    Squid#1:Screw that, im getting the Bimmer…

    Small oversigth(failed stupid Decibel test) turned into Big Fuck Up(Lost Sales).
    We all know we don’t need bikes as transportation (1Ks cost as amuch as a Compact Car with A/C now a days) and buying one is more about emotional impulse than logic or w/e.
    WHY settle for good(190 made number) when there’s better(197HP Bimmer,More POWAAAAAAHHH). Thats how NEW bikes buying Squids see it, almost positive.

    And to a lesser Xtent every regular JoeSchmo who likes Motorbikes.
    At the risk of sounding like a TOTAL SQUID im gonna say: I know i would…even tho I can’t use a fourth of it, it is good to know is THERE…POWAAAHHH! (O_O )’

  • gnmac

    F*** THE EPA!

  • CBR600RR 09


    I am sure everyone on this forum feels stupider for having read your illiterate spew.

    Please be kind to us and make sure you spell and grammar check before you post again.

  • MikeD

    Dear CBR600RR….: I don’t feel like doing such task, if it bothers you so much Copy and Paste my “Iliterate Spew” (wich i’m aware just how wrong is) with all that’s wrong Fixed. Do us all that Favor. The World will be a better place and less “Dumb”, i’m positive.

    Out of all things that someone could b!tch about my lousy/lazy typing was it, LOL, go figure.

  • CBR600RR 09

    @ML & @Hamza: It is not about that at all, it is all about “MINE IS BIGGER THAN YOURS”. Especially in the good old U.S of A and the side effects of promising too much and under delivering. Allow me…

    Squid#1 : Yo, that Kwakka that just came out got mad power, 197hp YO!
    Squid#2: True dat, but not anymore, it got it balls cut YO! Now it “ONLY makes 190″…Less than the Beamer…(or whatever happened to be fastest at said time)
    Squid#1: Screw that, im getting the Beamer…

    Small oversight (failed decibel test) turned into a big fuck up (lost sales).
    We all know we don’t need bikes as transportation (1Ks cost as much as a compact car with A/C) and buying one is more about emotional impulse than logic or whatever.
    Why settle for good (190 made number) when there’s better (197HP Beamer, more power).
    That’s how new bike buying Squids see it, almost certainly, and to a lesser extent every regular Joe who likes Motorbikes.

    At the risk of sounding like a TOTAL SQUID i’m going to say: “I know i would…even though I can’t use a fourth of it, it is good to know there is…Power”


  • MikeD


    Ur a Gentleman and a Scholar. Job well done.I feel smarter already.

  • Westward

    I can’t believe I read that twice, with the same amount of dread. I think I just lost a couple of IQ points…

  • MikeD

    @ Westward: LMAO…Priceless.

  • Super Ultra Mega

    Kawasaki lists peak horsepower as coming at 13,000 rpm, as per their company documents accompanying the release of the ZX-10R.