The Kawasaki GPZ1100 is a motorcycle that was manufactured by Kawasaki from 1981 to 1985. All models featured fuel injection and 1,089 cc engines.
The 1981 GPz1100 was the first 1,100 cc motorcycle released by Kawasaki. Rather than featuring carburetors, the B1 was fitted with electronic fuel injection (EFI) as used on the earlier 1980 Z1000G/H models. Suspension and braking was similar to earlier models; the front forks featured 38 mm tubes, the frame design, based on the z1000H and J models was made from larger diameter steel in the section between the steering head to rear of the tank. The engine output was increased by increasing the valve lift from 8.3 mm to 8.7 mm, and valve duration was increased from 280 degrees to 288 degrees to boost upper-end horsepower.
In 1983 a new GPz1100 design was released that featured Unitrack single suspension, anti-dive units on the forks and a major styling overhaul often called the "swish" look. Known as the ZX1100A1 model, the 1983 model featured a larger fairing, different instrumentation and a warning panel mounted on the redesigned petrol tank. The engine design changed in the 1983 model to use underbucket shims similar to the z650 and the camshaft duration was increased from 288 degrees to 300 degrees, and the valve lift increased from 8.7mm to 9.5mm. The power output was now claimed to be 120 bhp at 8,750 rpm. This model was released in a Red paint scheme with Blue and Silver stripes. Fundamentally the engine was still the same as earlier air-cooled engines.
The 1984 model deviated little from the 1983 model but featured a new paint scheme called "Galaxy Silver"; the original Firecracker Red scheme was still available. All specifications from previous models were retained.
In 1995, Kawasaki re-released the GPz brand, basing the motor on the ZX-9R/ZX-10/ZX-11/ZZR-1100 water-cooled engines. There is no similarity between the later models and any earlier models.