Kawasaki GPz900R: Top Gun

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Bike Reviews

By BikeReview - 10 May 2021

First released in 1984, the Kawasaki GPz900R A1 grabbed the attention of the buying public as a sportsbike and later in life as a mile-eating touring mount.

It could be argued that with the GPz900R, Kawasaki beat Suzuki and the GSX-R750F to the punch with a true racebike for the street offering both performance and handling.

The first fully faired modern superbike, the GPz900R sold faster than dealerships could assemble them.

Kawasaki engineers were tasked with building a machine that combined the handling of a 750 but with the power of a litre bike. Roughly six years passed from inception to public release, but the wait was well worth it with bikes literally flying off dealers’ floors as quickly as they could be assembled.

Liquid-cooling and 115hp. Amazing stuff for the era.

Producing 115hp at 8500rpm, the 908cc engine was the first production motorcycle inline four-cylinder engine to feature liquid-cooling, 16 valves and DOHC. According to a number of sources the all-new bike was the fastest production bike available with a well-proven capability of 240-plus km/h and was the first stock production motorcycle to exceed 150mph off the showroom floor.

The first Kawasaki Ninja. This was the most popular colour scheme as well.

A major part of the overall package was the very compact and liquid-cooled engine that was used as a stressed member. Compared to traditional bikes, the engine was carried low in the frame and this lower centre of gravity contributed to the fine handling as did the three-way adjustable anti-dive front-end and true rising-rate rear suspension. The all-steel chassis itself held no surprises with 16in and 18in wheels front and rear respectively, later changed to 17in at both ends in 1990.

The late great Len Willing made the GPz900R very famous here, including coming very close to a Castrol 6 Hour win at Oran Park. Pic: Phil Aynsley.

Not the lightest bike on the market at 228kg, the GPz900R was very popular with racers and street riders. An Australian print ad was photographed at the now defunct Castlereagh International Dragway that made drag racers chuckle as the bike was facing the wrong way! Pointed in the right direction, the GPz900R was capable of 10-second timeslips in the right hands making it the weapon of choice in the mid ’80s.

GPz900R Propoganda!

The riding position was roomy and definitely sporty behind the screen. Bars and switchblocks felt right with no hidden switches and the instruments, especially the all-important tach, were very easy to read and comprehend. Pillion comfort wasn’t forgotten with a generous pillion section on the seat and pegs that didn’t cut circulation to lower extremities.

Known problems in the early days were crankshafts and crankshaft bearings. Rest assured, any of them running now will have either had new bearings fitted or will have been from a later model run. The chain-driven camshafts were unique with a camchain running up the left-hand side of the engine. The chain is easy to replace but listen carefully for excess noise and be prepared to factor chain replacement into the purchase price. Accurate carby balancing is definitely mandatory on the GPz900R. When they’re synched properly, throttle response is crisp.

Typical of the era for Kawasaki, they still ran a heavy centrestand on their sportiest bike, making it a practical streetbike that became a known sports-tourer.

Between 1984 and 1992, the focus of the GPz900R shifted from pure-sports to sports-tourer and one of the greatest all-rounders of the era.