| Specification | Value |
|---|---|
| Model Series | EX500D (GPZ 500 S / Ninja 500R) |
| Production Years | 1994 – 2009 |
| Engine Oil | SAE 10W-40 (API SE, SF, or SG) – 2.8 Liters |
| Tires (Front/Rear) | 110/70-17 54H / 130/70-17 62H |
| Tire Pressure | F: 2.25 bar (32 psi) / R: 2.50 bar (36 psi) |
| Battery Type | YB14L-A2 |
| Spark Plug | NGK DR9EA (Gap: 0.6 – 0.7 mm) |
Engineering Legacy: The ‘Half-a-Ninja’ Engine
A unique engineering highlight of the Kawasaki GPZ 500 S is its liquid-cooled parallel-twin engine, which is essentially the architecture of a GPZ 1000RX (Ninja 1000R) sliced in half. By utilizing the same bore, stroke, and cylinder head design philosophy as its liter-class sibling, Kawasaki created a 498cc powerplant that was remarkably over-engineered for its category. This heritage allowed the EX500D to punch well above its weight, offering a high-revving nature and legendary durability that sustained its production run for over two decades.
The EX500D Evolution
The 1994 update, designated the EX500D, marked the most significant evolution in the model’s history. While the core engine remained familiar, Kawasaki addressed the previous model’s handling limitations by upgrading to 17-inch wheels. This change not only improved stability but also opened the door to modern radial tire compounds. Furthermore, the rear drum brake was replaced with a disc system, and the ignition system was modernized to enhance reliability under variable conditions.
Technical Maintenance Profile
Lubrication System
To maintain the high-revving nature of the EX500D, a high-quality SAE 10W-40 oil is mandatory. The engine requires approximately 2.8 liters of oil. Given the era of the design, owners should ensure the oil meets API SE, SF, or SG specifications to protect the flat-tappet cam followers and integrated gearbox.
Ignition and Electrical
The EX500D utilizes NGK DR9EA spark plugs. For optimal combustion efficiency and throttle response, the electrode gap must be precisely set between 0.6 and 0.7 mm. Electrical power is managed by a standard YB14L-A2 lead-acid battery, which requires regular checks of electrolyte levels to prevent premature failure.
Chassis and Handling
Proper tire maintenance is critical for the GPZ 500 S’s nimble handling characteristics. The standard fitment includes a 110/70-17 front and a 130/70-17 rear. For street performance, pressures should be maintained at 2.25 bar (32 psi) in the front and 2.50 bar (36 psi) in the rear to ensure even wear and predictable cornering feedback.
Editorial Verdict
The Kawasaki GPZ 500 S (EX500D) remains a masterclass in functional engineering. It bridges the gap between a beginner-friendly commuter and a spirited sport-tourer. Its technical simplicity makes it an ideal candidate for home mechanics, while its robust engine design ensures it remains a viable classic for the modern rider.