Kawasaki Z650

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Kawasaki Z650
KZ650
Manufacturer Kawasaki Motorcycle & Engine Company
Parent company Kawasaki Heavy Industries
Production 1977-1983
Class standard
Engine 652 cc (39.8 cu in) inline four
Bore / stroke 62 mm × 54 mm (2.4 in × 2.1 in)
Compression ratio 9.5:1
Top speed 115 mph (185 km/h)[1]
Power 62 hp (46 kW) @ 8,500 rpm (claimed)[1]
Torque 41 lb⋅ft (56 N⋅m) @ 7,000 rpm (claimed)[2]
Ignition type points, then CDI
Transmission 5-speed, chain final drive
Frame type double cradle frame
Suspension Front:36 mm telescopic forks
Rear: twin rear shocks
Brakes Front: single or twin 275 mm (10.8 in) discs
Rear: 180 mm (7.1 in) drum or disc
Wheelbase 1,420 mm (55.9 in)
Weight 465 lb (211 kg)1976-1977[2](dry)
493 lb (224 kg)1978-1981[1] (dry)
485 lb (220 kg) (wet)
Fuel capacity 16.8 L (3.7 imp gal; 4.4 US gal)

The Kawasaki Z650 (known as KZ650 in North America) was a 652 cc (39.8 cu in) standard motorcycle made by Kawasaki from 1976 till 1983. It featured a four-cylinder four-stroke DOHC air-cooled wet sump engine with two valves per cylinder and a five-speed gearbox. Designed as a middleweight sibling to the Kawasaki Z1, it competed in the market against the smaller SOHC Honda CB650. The Z650 was the epitome of the "Universal Japanese Motorcycle", or "UJM".[1]

Model development[edit]

The Z650's project leader was Mr Inamura. In its seven-year history, the Z650 underwent a number of iterations, as follows:

1977 Z650/KZ650[edit]

1977 KZ650 with wire -spoked wheels & drum rear brake

This first Z650 had a single front 275 mm disc brake and a 250 mm rear drum. Although the Z650's engine was based on the 900 cc (55 cu in) there were several differences: the 650 used a plain bearing crankshaft with a HyVo (or "Morse") chain primary drive instead of a gear drive, which necessitated the installation of a third (intermediate) shaft in the transmission to drive the input side of the clutch. Another departure from the Z1 engine design was the use of a shim-under-bucket method of setting valve clearances. (The Z1 engine's shim-over-bucket design caused some mishaps when its camshafts flicked the shims out of position, with consequent damage).[2]

1978 Z650/KZ650[edit]

The front brake caliper was resited to the rear of the fork leg and the front master cylinder reservoir shape was changed. A hazard switch was added. Needle roller bearings were fitted to the swingarm instead of the earlier plain bushings. Tuning modifications were made to the carbs to improve low speed operation. The manual operation fuel tap was replaced with an automatic diaphragm unit. A rear disc brake replaced the earlier drum.

A customised Z650

1979 Z650/KZ650[edit]

This model featured a self-adjusting (rather than manually-adjusted) camchain tensioner. For US-only models, an air injection system for emissions reduction was fitted. This model was the first Kawasaki to use all-weather sintered disc pads and drilled brake discs to improve braking in the wet. A derivative version, the KZ650SR had "chopper styling"[1] with a fat 16-inch rear wheel.

1980 Z650/KZ650[edit]

A HyVo-type timing chain replaced of the earlier roller chain.[3] An "LTD" model became available with just a single front disc brake and a rear drum brake.[3]

1981 Z650/KZ650[edit]

CDI ignition (instead of points) was introduced. The front end from the 750E was grafted on meaning a change to the brakes, front wheel and clocks[citation needed]. The kick-starter was removed and a passenger grab rail was fitted. Larger 32mm Mikuni CV carbs were fitted, allowing the redline to be lifted from 9,000 to 9,500 rpm. A new generation of Kawasaki cruisers, the "CSR" was introduced.

1982 Z650/KZ650[edit]

Changes included new CV carbs, a clutch upgrade, modified fork internals, new switchgear, tail light, and different rear shocks.

1983 Z650/KZ650[edit]

Some minor updates including new pistons with four rings, and changes to the cylinder head and cover. After 1983 the KZ650 is surpassed by the GPZ models.[2]

See also[edit]

References[edit]

  1. ^ a b c d e Hall, Landon (September–October 2007). "1978-1981 Kawasaki KZ650SR". Motorcycle Classics. Retrieved April 21, 2017. 
  2. ^ a b c d "Kawasaki Z650 Road Test". Classic-Motorbike.net. December 1, 2011. Retrieved July 19, 2017. 
  3. ^ a b Kawasaki Service Manual Part #99924-1007-03 3rd ed. dtd. September 10, 1981, p. 289