1998-2003 Kawasaki ZX-9R - Coming Up Nines

In today's world of one-liter superbikes, it may be hard to imagine that a little more than a decade ago, 900cc used to be the engine size that dominated the streets. Kawasaki was the company that started the age of the modern liquid-cooled superbike with the original Ninja 900 (technically known as the ZX900 A1 model) that was first introduced in 1984. Its popularity was such that it even made an appearance in the iconic 1985 movie "Top Gun". But the first big-bore Ninja became the forerunner to a machine that truly cemented that moniker's performance heritage in the Kawasaki history books.

Although the ZX900A model was technically in the company's U.S. lineup until 1996, it had become geared more toward a sport-touring image by then. Kawasaki had already been hard at work designing a successor, and released a new model in 1994 that was eons ahead of the previous lineage. Basing the engine and chassis on its already successful ZX-7R, the ZX-9R boasted serious power that whupped on its competition (some sporting larger engines) with higher top speed and quicker quarter-mile times. Sharper steering geometry and compression damping adjustability in the rear shock helped it carve corners just as well as it inhaled straights.

With such a ground-breaking design, you would assume the new ZX-9R had to be latest and greatest at the time, right? As luck would have it, though, 1998 also saw the debut of the Yamaha YZF-R1. The Yamaha pretty much stole the limelight from the Kawasaki in the public's eye, which was unfortunate, because the 9R-while lagging in the spec sheet in certain areas-certainly wasn't a slouch at the track. For instance, although the ZX-9R was 15 pounds heavier, our test units consistently cranked out about five more horsepower over the comparable R1 test bikes (and it should be remembered that the 9R was doing this with 99cc less displacement). Despite the smaller engine, the Ninja was usually just a hair faster than the Yamaha at top speed. It also was the first stock production machine to run a nine-second quarter-mile back in the day, with SR's El Jefe hustling a stock ride height/stock gearing/stock tire-equipped ZX-9R to a run of 9.99 seconds at 136.8 mph.

In order to carve the weight off the previous bike, Kawasaki engineers amazingly shaved off almost 50 pounds from the chassis and running gear, and another 19 pounds from the engine. The 55.7-inch wheelbase was almost a full inch longer than the R1, but the result was a bike that was a lot more stable. While the R1 was known to be a bit nervous when ridden hard, the Kawasaki remained rock-solid even though it didn't come with (or really need) a steering damper. Ergos were also significantly more street-biased compared to the other bikes in its class, with higher clip-ons, more legroom, and better fairing protection making the Kawasaki a sportbike that could inhale miles without punishing its rider.

The inline four-cylinder engine sported a more oversquare 75 x 50.9mm bore/stroke configuration than the previous generation (2mm larger bore, 2.8mm shorter stroke). This allowed the lighter crankshaft to spin higher (12,500 rpm versus 11,500 rpm for the old model) and fit bigger valves, up 1mm on both the intake and exhaust compared to its forerunner. Kawasaki also employed more aggressive cams although compression remained the same at 11.5:1.

Kawasaki's pioneering development of ram-air technology to boost power continued with the latest generation 9R, with twin ram-air intakes just under the front headlights helping to increase airbox pressure at speed. The fueling was handled via a quartet of Keihin 40mm carburetors, equipped with throttle position sensors that were part of the K-TRIC (Kawasaki Throttle Response Ignition Control) ignition system. Not only did this setup optimize ignition curves by monitoring throttle position, but also the rate of throttle opening. The result was better fuel economy (about 40 mpg) as well as improved throttle response and less detonation at low rpm.

In 1998 the bike retailed for $9999 making it a solid deal compared to the over $10K of the Yamaha R1. Pricing on the bike stayed flat until 2000, when it bumped up to $10,199 then in 2002 it dropped all the way back to $9499 and stayed there for 2003 as well, no doubt a sign of its future.

The 2002 model year arrived, and one final upgrade was made to the ZX-9R. Front brake rotors were once again increased in size to 320mm. The crankshaft weight was increased by 10 percent to help smooth power output, with the 40mm carbs getting some minor updates. Chassis was stiffened with different engine mounts, and a swingarm brace was added; the drive chain was shrunk to a 525 from the previous 530. Weight, however, grew by about 10 pounds.

The aftermarket was full of go-fast-goodies for the Ninja back in the day. The top modifications included full exhausts, jet kits, ignition advancers, air filters and 520 chain conversions kits topping the list. The most popular full exhaust systems of the day included Muzzys, Akrapovic, and Hindle. Weight loss from getting rid of the stock exhaust wasn't as big as the old days or even today with the heavy under-engine exhausts, but you can expect to lose 10 pounds or more depending on the system you choose.

Muzzys also offered an ignition advancer that was very popular and once installed it resulted in a nice bump in low-midrange power. Factory Pro Tuning Components and Ivan's Performance both had quality jet kits that are reported to be almost drop-in ready. K&N and BMC were the most popular air filters. With all of the above mods, you could expect about 140-145 horsepower, which is about 15 horsepower above stock. Not bad considering this was 1998 and you were working with only 899cc.

If that was not enough power you could also order up a Muzzys Big Bore kit, which boosted displacement up to 998cc and well over 155 horsepower. Webcam also made high-lift cams, and larger diameter valves could be ordered from APE Race Parts if you really wanted to go all out. The ZX-9R was a great platform for many years due to its reliability and a strong engine. The result was a wide range of high performance bikes that ranged from track day sportbikes, to dragstrip-only versions. Even turbocharged ZX-9Rs can be found today.

Some serious riders did install a steering damper for track day use, but in general we don't see as many of these bikes with dampers fitted. The ZX-9R was stable enough with its longer wheelbase that it wasn't much of a problem. Those looking for lap times turned to Penske, Lindemann Engineering or other suspension gurus to upgrade the rear shock and fork internals. We also found quite a few with brake upgrades from Galfer and EBC.

If you were more of a sport-touring rider you could opt to install some HeliBars to further raise the already comfortable clip-ons to a more manageable height. Then it was a simple matter to slap on a tank bag or soft side bags and you were good for a long weekend on a surprisingly comfortable sportbike.

If you were more of a sport-touring rider you could opt to install some HeliBars to further raise the already comfortable clip-ons to a more manageable height. Then it was a simple matter to slap on a tank bag or soft side bags and you were good for a long weekend on a surprisingly comfortable sportbike.

The bike was generally a reliable package with the only real mechanical malady coming from a 3rd gear issue in the early '98-'99 models. If you're looking at a ZX-9R from this era, pay particular attention to the 2nd-3rd gearshift; any signs of poor engagement point to a future rebuild. The early 2000 models had an issue with a frame crack, but it didn't last long in the production run so not many bikes were affected by this problem.

Lee Shierts, owner of Lee's Performance in Charlotte, North Carolina and the title of "the fastest man on a streetbike" (running over 260mph at Maxton's Monster Mile), told us, "the ZX-9R was a bulletproof bike mechanically. We built a lot of them for dragracers, and they held up and ran well at the strip compared to the other bikes available in '98. But I sure don't miss having to jet carbs like we did on the bikes back then. EFI has really made tuning a lot easier."

Owners of ZX-9Rs are quite happy with the bike's superb all-around performance. "The ZX-9R is unbeatable as an all around bike," says Matt Warner of Sherrard, Illinois. "It's quite comfortable in stock form with great power and handling for the time. With a few minor mods it's as comfy as a sport tourer with the weight and power of a pure sportbike. I can't think of any one bike produced today that even comes close to equaling its capabilities as an all-arounder."

Though the ZX-9R was often overlooked, the Kawasaki really was the best streetbike in the class, which explains the popularity it enjoys even through today. It was fast, reliable, and easily modified with a wide range of aftermarket support. The good news is that if you want to pick one up on the used market, the damage on your wallet is not too bad either. After checking NADA average retail prices we see that 98-99 models can be had for $2635-$2730. If you move up to the 2000-2001s expect to pay $3420-$4015. The 2002-2003 models of course are newer but carried the lower retail price back then, expect to pay $4270-$4740 for the last two years of the bike that was the basis for the today's ZX-10R.