The extra 36cc to be found in the Kawasaki 6R motor gives the rider some serious mid-range and low speed drive ability from as early as 3000rpm if needed. There is no pronounced step in the power, or holes in the power band, and the engine pulls strongly all the way till the shift light tells you its time to change up around 15,000rpm.

This year’s bike makes ten more horsepower than last year’s model for a quoted 136hp at 14,000rpm with ram air assistance. This has been achieved with some significant work to the top end of the engine. Starting in the cylinder head, the ports are treated for extra smoothness, and larger valves are placed further apart to get fuel in and out faster.  The previous higher lift race kit cams open and close the valves while new pistons are claimed to reduce friction and realise an increased compression ratio.

Larger 38mm throttle bodies help to boost the power and they are now oval shaped to save width.  Firing fuel into the bigger, more efficient throttle bodies is a dual injector system; utilizing extra-fine atomizers in the throttle bodies which are now joined by a secondary set of injectors in the airbox.

A new centrally located, more efficient ram air system is now used to help the extra fuel do its job in the combustion chamber. The result of these changes is absolutely perfect throttle response anywhere in the rev range in any gear.

Our first couple of sessions on the track were ridden in damp, cool conditions, and there is never a more important time to have smooth throttle response. The system is so perfect, I was able to run low gears and high rpm to better control my corner exits, the small throttle openings needed to make forward progress giving instant, smooth trouble free power on demand.

Rolling off and back on the throttle again where needed the smooth response inspired confidence and allowed me to circulate the damp track with at a reasonable clip.  If there were any problems to be found in the system, those first sessions would have most certainly showed them up.

No prizes for noticing the new exhaust. With its fashion following under tail routing, it gives the bike a very clean and sleek look. What you can’t see is the internal exhaust valve. A first for a Supersports bike, an ECU reads engine revs and throttle position to determine when to open or close the valve. This helps the ZX-6R make better low and mid-range power, and only gets praise from this corner, especially on the rain soaked mountain roads around the Circuit Almeria during our street ride. The exhaust system also gets a catalytic converter in some markets for cleaner running.

Before moving on, there are a couple more things to note with the drivetrain. Firstly, a slipper clutch is now employed to help with premature down shifts. While I never used the feature it was a comforting feeling when peeling down from around 150mph on the back straight going down through the box to second gear for the next right-hander. 

The engine cases have been beefed up to handle the extra power, and a deeper sump is used to lower the amount of oil circulating around the moving parts in the upper end of the engine.

There are some slight changes in the transmission also with a new bearing on the shift drum locator arm for better shifting, a taller third gear, and needle bearings at the end of the transmission shafts for greater strength. I didn’t have any problems with the previous model’s gearbox and certainly didn’t experience any with the ’05. It shifts with silky smooth precision and no missed gears made it into my notebook over the two days.

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