The Kawasaki Z500/Z550 series began with the 1979 Z500, a scaled-down version of the Kawasaki Z1R.
It used a double-cradle steel (Norton featherbed-style) frame with a transverse-mounted air-cooled 4-cylinder DOHC (Double Over Head Cam) engine—a classic universal Japanese motorcycle.
In performance, the Z500’s engine matches the chassis perfectly. Peaking at a claimed 52bhp at 9,000 rpm with the red line marked at 9,500 rpm, it easily urges the bike to almost 1 lOmph flat out and puts indicated cruising speeds of around 90mph comfortably in the grasp of the rider even when there’s only small sections of open road to play with.
Much of the engine’s excellent power is derived from the use of double overhead camshafts and the four free-breathing 22mm-choke Tekei carburettors. Like the Z650 and the old CB500, the four-throw crank runs in plain bearings and drive is through a Morse-type chain and gears to the wet clutch. Bore and stroke are the same as the Z250; 55 x 52.4 mm. But new is the use of another Morse-type chain with an automatic adjuster for driving the camshafts.
Some of the surprising snap throttle response and startling acceleration is derived from the six-speed gearbox and wide ratios. Gear change action is slick and noiseless and the ‘box retains the useful neutral-finding dodge that stops you selecting second from bottom at a standstill.
Kawasaki appear to have selected the gear ratios with drag racing in mind for the reve drops between gears are as similar all the way through the range instead of having a large gap between bottom and second and closing up the other ratios. In normal use though the engine is so flexible, pulling cleanly and usefully from as low as 1,000 rpm in top, that the lower ratios hardly ever get used.
At the test strip though the effect is obvious. The Z500 fires like a cannon from the gate to be easily the quickest-accelerating 500cc machine on the market getting to 60 mph in 6.5 seconds. The tractability has advantages in fuel consumption too. The Z500 returned just over 52 mpg despite being thrashed giving at worst 175 miles on a tankful.
With no kickstart lever, it’s just as well the self starter was reliable. The engine fires up cleanly and is helped on cold mornings by the throttle-valve lifter incorporated into the choke mechanism. The clutch was annoying though. Like an old Triumph, it would stick after being left overnight. Unfortunately, and to our surprise, the worst feature of the Z500 is vibration. When used as a sports bike in the twisties it’s doubtful if you’d notice it, but on motorways the vibes above 5,000 rpm are enough to render the rear-view mirrors useless.
General characteristics
Engine: Air cooled, four stroke, transverse four cylinder, DOHC, 2 valve per cylinder.
Capacity: 497
Bore x Stroke: 55 x 52.4 mm
Compression Ratio: 9.5:1
Induction: –
Ignition / Starting: electric
Max Power: 52 hp @ 9000 rpm)
Max Torque: 4.5 kgf-m @ 7500 rpm
Transmission / Drive: 6 Speed / chain
Front Brakes: 2x discs
Rear Brakes: Single disc
Front Tyre: 3.25-19
Rear Tyre: 3.75-18
Dry-Weight: 174 kg
Fuel Capacity : 15 Litres
