Sonoma, CA -- It sure is nice to live in a world where most everyone can reap the benefits of someone else's smart decisions or discoveries. Penicillin comes to mind. Louis Pasteur ranks pretty high on my list of all-time greats, and I'm a fan of the establishment of the Declaration of Independence of the United States of America.
Are you still reading and wondering what this has to do with the 2007 Kawasaki Z1000? In my opinion the revamped Z is the result of two good decisions that benefit the American rider.
Whether it's simply a matter of design cycles or an earnest desire to reward the buying public, Kawasaki made a host of changes to the exciting but flawed Z1000. So many things were tweaked or replaced that the list reads like a new bike introduction.

Rap sheet or laundry list?
Team Green had some serious objectives for the '07 Z1000. They wanted to bulk-up performance, refine the chassis, revise the riding position and give it a make-over. So where did they start?
Though the engine didn't receive a major overhaul, a few key items were altered internally on the ZX-9R-derived 953cc DOHC inline-Four. In order to bias the torque curve with more low- and mid-range oomph, cam profiles were changed and intake and exhaust valves were reduced by half a millimeter from 2006 dimensions. New cylinder casings are claimed to reduce pumping loss, and an altered oil pump gear ratio allegedly contributes to reduced mechanical losses. Kawasaki has aimed these changes to improve low and mid-range performance, addressing some complaints about the previous model's relatively modest bottom-end power. I say it's torque-licious.


Down in the basement, flywheel mass was increased 7% from '06 and the final-drive gearing has been lowered ever so slightly. Work continued in the tranny package by reshaping the shift cam and adding ball bearings to the shift lever. Reduced clutch effort is provided by lower-rate clutch springs. Finally, the radiator was lightened and its cooling capacity increased by 18%.
Anything else that's changed on the powerplant is primarily external and mostly cosmetic.
Feeding the four hungry 77.2 x 50.9mm cylinders with a compression ratio of 11.2 is the job of an all-new fuel injection system. Smaller 36mm throttle bodies (from 38mm), oval-shaped sub-throttles (instead of the round units from last year), and injectors that spray an ultra-fine mist in a new pattern have been implemented in the hopes of providing a responsive and smooth feel at your right wrist.
What's left of the fuel mixture after it endures the swirling firestorm of combustion gets shuttled out through a revised "iconic exhaust system." Knowing the distinctive four-pipe look had grown on people (and grated on others) over the past four years, Kawasaki didn't want to give up the signature piece of the Z's appearance: the over-under shotgun quad exhaust system. Though it went from a 4-2-4 to a 4-2-1-2 this year, it still has the heart of the older model's look with two end caps per exhaust can. You can fool some of the people some of the time...
They may be trying to placate those quad-exhaust lovers of you out there by keeping a familiar look, but there's more than meets the eye.
Hidden away in the right-side exhaust, just ahead of the silencer, is a valve designed to "tune back-pressure waves for enhanced response in the low-mid range," according to Kawi press materials.
(And if it helps the Z pass EPA noise regulations, too, so much the better. -Ed) As if that wasn't enough, the whole system is said to be lighter than before, no matter what your eyes tell you.


According to MO's dyno last year the '06 Z wicked up 127 hp at a smidgen over 10,000 rpm with 69 ft-lbs. of torque almost dead on 8,000 rpm. Kawasaki didn't provide claimed horsepower figures for '07, but the provided spec chart boasts a torque figure of 73.1 ft-lbs at 8,200 rpm, up slightly from the crankshaft claim of 70.5 at 8000 rpm for the old model. Kawi product manager Karl Edmondson estimates that the new Z is probably down a top-end pony or two from last year due to the new focus on low-end grunt.
The biggest drawback to the Z of the past four years was the ridiculous amount of engine vibes that made their way to the rider. The previous bike had three rigid motor mounts (one in front of each outer cylinder and one near the footpegs) and one rubber mount (just above and behind the counter-shaft sprocket cover).
For 2007, Kawasaki designed a cast-aluminum engine sub-frame to relocate the forward mount from the front of the cylinder to the rear, leaving the two remaining mounts where they were. The result is an improvement in the bike's CoG of the engine and an intended reduction in chassis flex, in addition to quelling obnoxious vibration. Additional frame mods have the steering head moved forward 10mm that helps cause the wheelbase to grow from 55.9 to 56.9-inches. As part of the frame package, the new swingarm is constructed of pressed aluminum. As a whole, frame rigidity has been reduced by 15% for an improvement in feedback to the rider.
Kawi engineers also gave the suspension a once over, going to a 41mm inverted Showa fork (previously Kayaba units), with variable rebound damping and flush-style preload adjusters. Kawi says the fork is smoother in the upper half of the stroke while getting firmer as the fork is compressed. Attached to the new Bottom-Link Uni-Track swingarm is a Showa piggyback reservoir shock with twin-locking-ring preload adjustment and step-less rebound damping.