Kawasaki ZX-12R: Future Classic

Date 09.6.2015

Presented by
  • Motorcycle Trader



Kawasaki ZX-12R

The Kawasaki ZX-12R had troubled beginnings, none of which were of its own making. Delivery delays, forced engine reconfigurations before and after release, politics – the list went on.

Looking to build a hyper-sports motorcycle that would claim the mantle of the fastest production machine on the planet, the pre-production units were indeed faster than Suzuki’s iconic Hayabusa – the bike Kawasaki had smack-bang in its marketing cross-hairs.

When the big Kwaka finally made it to showrooms in 2000, the bike featured a detuned version of the engine fitted to the prototypes. European legislators got wind of the rumoured top speed of approximately 310km/h and were threatening to ban the bike. As a consequence, Suzuki kept the ‘fastest’ title, although our discussions with ZX-12R owners have challenged this claim. This only serves to prove that the theory of ‘build the fastest and they will argue’ was as true in 2000 as it is today.

Kawasaki worried some more with the 2001 incarnation, fitting limiters to keep top speed to 300km/h. An agreement followed among major Japanese manufacturers to voluntarily limit their bikes to 299km/h. While the numbers are largely academic, the move was eminently wise, although roundly criticised by motorcyclists at the time.

This allowed the European governmental furore to settle down despite the ZX-12R still being one hell of a fast motorcycle.

Dry weight at launch was 213kg and output was a claimed 131kW at 10,500rpm and 134Nm at 10,200rpm. Yes, big top-end was the order of the day. The engine is an 1199cc, liquid-cooled, fuel-injected, DOHC, inline four. It’s what you would expect from Japan at the time and remains the likely configuration were the bike to be launched today.


The ZX-12R was extensively wind- tunnel tested and was substantially narrower than any machine in its class at the time due to the frame design.

It’s a substantial motorcycle and the entire ZX-12R model range offers real-world appeal for those of bigger stature.

In the never-ending chase for lighter weight, sportsbike manufacturers continue to miniaturise their offerings – no such silliness hinders the ZX-12R. If you are of heft, this one will fit. If you’re size-challenged, then best look elsewhere.

After its aforementioned teething issues, the first of the ZX-12R lineage (A1) was relatively well-received although it has to be said it was damn expensive at around $20,000.

Off the shop floor, complaints centred around erratic throttle response from the bottom of the rev range. The ZX-12R was easy to stall as a consequence. Interestingly, the A1 escaped the dreaded speed limiter and is capable of 305km/h. This significantly adds to the allure for a collector and should be borne in mind for a used buyer.

For those looking to bypass the speed limiter, this is relatively easily done. Google ‘yellow box speedo recalibrator’, and all the information is there. The unit basically tells the engine that it’s doing a different speed than it actually is and hey presto – no more speed limiter.
We didn’t tell you this.

The ZX-12R was recalled in December, 2000 to replace the overflow pipe inside the fuel tank as it could crack and leak. Another recall in October, 2001 addressed tyre valve nuts, which could crack from corrosion or stress leading to a loss of pressure.

It was a small problem that could lead to a big one very quickly.

Check the rear shock. These were known to lose damping relatively early in their lives. Factor this in when haggling: if there’s little damping, you’ll be up for a shock. Pass on the cost.

In 2002 Kawasaki released the B1 with new bodywork, ram air intakes and gearbox tweaks. The engine was retuned for more off the bottom and the crankshaft was strengthened.

Oddly, you couldn’t buy the bike in Kawasaki Green.

The 2002 bike was even more refined, although power was slightly down due to that heavier crank. A narrower flywheel was also used, as were oval throttle pulleys which helped in the low to mid range.


The B2 was released that November and recalled in January 2003 because oil could seep through the wiring harness connected to the stator, allowing oil to make its way to the rear tyre. All recall details are available from Kawasaki if you are uncertain whether or not any work has been carried out.

The 2004 model year saw radial brake calipers fitted to the ZX-12R (owners suggest the brakes were greatly improved by this), and Kawasaki engineers again fiddled with the fuel injection to boost throttle response.

From 2004 until the bike’s discontinuation in 2006 there were no major changes (B4-B6F).

Areas to check on the ZX-12R are right across the model range rather than problems and idiosyncrasies that normally beset particular models. This is a good reason to consider the ZX-12R – the important stuff was right from the beginning. The main reason for this is the fact that the ZX-12R drivetrain is the bike’s strong point. It’s the choice base unit for drag racers worldwide, and there can be no better recommendation – quarter-mile nuts gain serious output figures and the Kawasaki engines hang together under huge stresses. Gearboxes and clutches are as strong as they get. Tough as.

There are issues. If the bike has K&N-style aftermarket air filters, check the way they are fitted because they’re prone to leaking due to the restricted space available.

Ensure the fuel-injection light is not illuminated. ZX-12Rs have a tendency to break throttle position sensors and it’s impossible to buy them individually. You’ll have to buy a full set of throttle bodies and this ain’t cheap. If the light is on, further diagnosis is recommended before handing over the shekels.

Front guards strike the underside of the upper fairing when pushed hard. Look for tell-tale signs here. If there are witness marks, you are looking at a bike that’s spent some time with its front wheel in the air, with the subsequent hard landings putting big stresses on the front end.
The bolts that secure the upper fairing often come loose. This pops off the fasteners on the inner fairing panels. Look at the points where the fairing frame mounts to the main frame and ensure these mounts are well secured and in good condition.


Fast. Wickedly, angrily, aggressively fast. This is a testosterone charger, a tour de force – there is little about the ZX-12R that’s subtle. You’ve got oodles of horsepower and you’ll never need more than the Big Z possesses. Trust us.

The bike has two stages of power – from around 2000rpm, easing in the mid range and then gathering up a momentous head of steam again at 8000rpm through to redline. It’s a very exciting thing to ride.

This is a great used buy. Underrated and less fancied than the Hayabusa, but with no good reason. That’s good news for you: used prices reflect that fact, and there are real bargains out there. This one comes highly recommended.