| Specification | Data |
|---|---|
| Production Years | 1981 – 1983 |
| Engine Type | Inline-4, Air-cooled, DOHC |
| Drive System | Shaft Drive (ST) |
| Oil Capacity | 3.2 L (Change) / 3.7 L (Dry) |
| Spark Plug | NGK BR8ES |
| Battery Type | YB14L-A2 |
A unique engineering highlight of the Kawasaki Z 1100 ST (KZT10A) is its specific adaptation of the high-torque 1089cc engine to a shaft-drive system—a configuration borrowed and refined from the legendary Z1300. Unlike its chain-driven siblings, the ‘ST’ (Shaft Transmission) was engineered specifically for high-speed continental touring, featuring a reinforced frame to handle the unique torsional loads of the shaft drive while maintaining the classic ‘Z’ silhouette.
Engineering Overview
The KZT10A represents the pinnacle of Kawasaki’s air-cooled, eight-valve era. While the market was shifting toward liquid cooling, the Z 1100 ST doubled down on displacement and reliability. Its 1089cc powerplant delivered smooth, linear power, making it a favorite for long-distance riders who demanded the low-maintenance benefits of a shaft drive without sacrificing the raw performance of the Z series.
Maintenance Guide & Fluid Specifications
Proper lubrication is critical for the longevity of this air-cooled engine. At MotoSpecsLab, we recommend adhering to the following fluid standards:
- Engine Oil: SAE 10W-40, 10W-50, 20W-40, or 20W-50. Ensure the oil meets API SE/SF standards.
- Capacity: 3.2 Liters for a standard oil and filter change; 3.7 Liters for a total dry fill.
- Spark Plugs: The KZT10A requires NGK BR8ES plugs, gapped to factory specifications to ensure efficient combustion across the broad powerband.
- Electrical: The system relies on a YB14L-A2 battery. Given the heavy cranking load of the 1100cc pistons, maintaining a healthy charge is essential.
Chassis, Tires, and Handling
The Z 1100 ST is a heavy machine, and tire selection is paramount for stability. The factory-specified dimensions are:
- Front Tire: 110/90-19 62H
- Rear Tire: 130/90-17 68H
Tire Pressure: For optimal handling, maintain 2.0 bar (28 psi) in the front. The rear requires 2.25 bar (32 psi) for solo riding, which should be increased to 2.8 bar (40 psi) when carrying a passenger or heavy luggage to prevent sidewall overheating.
Expert Verdict
The Kawasaki Z 1100 ST remains a masterclass in early 80s over-engineering. It offers a unique riding experience that blends the mechanical soul of the original Z1 with the civility of a modern tourer. For the collector or vintage enthusiast, the KZT10A is a robust platform, provided the shaft drive seals and oil levels are monitored diligently.
Frequently Asked Questions (FAQ)
What is the oil capacity for a filter change?
The Z 1100 ST requires 3.2 liters of oil when replacing the filter.
Can I use synthetic oil in the KZT10A?
While modern synthetics are superior, ensure they are compatible with wet clutches and meet the vintage API SE/SF requirements to avoid clutch slippage.
Why is the rear tire pressure so high when loaded?
The shaft-drive assembly adds significant unsprung weight. Increasing pressure to 2.8 bar (40 psi) ensures the tire profile remains stable under the combined weight of the bike and cargo.