Should I Not Buy a Z900RS Because of "Throttle Abruptness"?

Dear Tony,

It’s a shame it’s so hard to get a test ride on so many Japanese motorcycles, because the whole “abrupt throttle” brouhaha mostly comes down to a personal thing: Some people are really bothered by it. I read a couple of reviews where the Kawasaki Z900RS’ throttle abruptness was the main theme. For me it wasn’t really a big deal, and in the review I wrote for MO at the bike’s launch, I said the Z “does suffer a bit of throttle abruptness occasionally when things get aggressive in the curves. By no means a deal-breaker.” By that I mean that when you first crack the throttle on, there’s a bit of a lunge when the computer first injects fuel. It also didn’t help that we were riding really tight, bumpy backroads when I felt that behavior, which many times is just your throttle hand bouncing around on the grip.

If you’re roadracing, you really need the power to come in smoothly because you’re generally on the very edge of tire adhesion when you want to open the throttle. For a streetbike like the Z – especially a retro one designed more for cruising around than ultimate sport performance, that throttle abruptness seldom even registers in my brain. When I want to take up the cudgels on curvy backroads, it seems like one finger on the clutch and a toe on the back brake are all you need to do to tame that behavior, things I’ve learned to do subconsciously over the years anyway. (Which is not to say that some of the other journalists who complained about the Z aren’t really good riders.)

That bike’s been with Brent Jaswinski the last few weeks. Brent’s a really good rider, who does a lot of MX and off-road too. Here’s his take:

“The Z gets looks and compliments everywhere you go. It rides and performs well too, but there is definitely something to be said about its abrupt throttle response. There’s a big hit when you initially open the throttle and likewise when you close it with engine braking. Modulating the throttle is smooth and fine once it’s already open, but the initial open and close just about anywhere in the rev range definitely jerks the rider a bit.

“I’ve put a good 300+ miles on the Z900RS so far and from what I’ve learned about it, basically, is that you need a very smooth and calculated throttle hand. Getting used to the throttle may be a concern at first, but the more you ride it, the less you end up thinking about it. Just like a touchy clutch or front brake, it’s just something to get accustomed to because each bike is different. I don’t know if I’d call it a flaw so much as I’d call it a quirk.

“Once riding, it’s kind of fun to play around with the throttle while figuring out how to rev-match and once you get it down it’s really not that bad.

“What I do know, is that there will be some absolutely killer, custom raced-out Z900RSs out there in the near future with rear sets that won’t have the pegs scraping so early and different, racier bars. The Z900RS may have its rough edges, but what hot rod doesn’t?”

Brent-the-chopper-guy’s last sentence resonates with me, too: I grew up with the idea that a big engine producing big horsepower isn’t going to always be a perfectly smooth-performing vehicle.

Will Kawasaki refine it for year two? I wouldn’t be surprised, given all the complaints, but are we sure that’s what we want? I happen to be sitting next to a 2018 Suzuki GSX-S1000, whose throttle abruptness Suzuki addressed following complaints about it. (I tried to smooth out the GSX-S with a Flash Tune reflash here, partially successfully.) That 2016 Suzuki made 143 hp and 76 lb-ft of torque. The smooth-running new 2018 we ran on the dyno a couple weeks ago, which really is way less “abrupt,” makes 134 hp and 72 lb-ft. That’s still plenty of power, but 9 hp is 9 hp. Maybe you can’t have everything?

Send your moto-related questions to AskMOAnything@motorcycle.com. If we can’t answer them, we’ll at least do no harm in the time it takes to seek out a believable answer. And we’ll occasionally even admit we were wrong, even if we were right at the time. Depends on what the definition of “is” is.

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