| Component | Specification |
|---|---|
| Production Years | 1990–1995 |
| Engine Oil | SAE 10W-40 (API SF/SG) |
| Oil Capacity | 1.1 L (1.3 L with filter) |
| Tires (F/R) | 80/100-21 / 110/90-18 |
| Spark Plug | NGK CR9E (0.7–0.8 mm gap) |
| Battery | YTX5L-BS |
Engineering Heritage: The SACS Influence
The Suzuki DR 250 S (SG42A) stands as a pivotal moment in dual-sport evolution. While many competitors relied on basic air-cooling, Suzuki implemented a variant of the Suzuki Advanced Cooling System (SACS), a high-flow oil cooling technology originally developed for the legendary GSX-R750. This allowed the SG42A to maintain tighter tolerances and higher reliability under the thermal stress of slow-speed technical trail riding.
Technical Performance & Handling
The SG42A is powered by a 249cc, DOHC, 4-valve single-cylinder engine. Unlike the more aggressive ‘R’ version, the ‘S’ (Street) model features a balanced flywheel and a CV carburetor that prioritizes linear power delivery over explosive torque. This makes it an exceptional platform for both beginner off-roaders and seasoned green-laners seeking a lightweight, manageable machine.
Maintenance Guide
Lubrication System
To ensure the longevity of the SACS-equipped engine, use a high-quality SAE 10W-40 oil meeting API SF or SG standards. The oil change volumes are critical: 1.1 liters for a simple drain, 1.3 liters when replacing the filter, and 1.7 liters after a full engine rebuild (dry).
Chassis & Tires
The SG42A utilizes a classic 21-inch front and 18-inch rear wheel configuration, providing access to a wide range of enduro and dual-sport rubber. For optimal street/trail balance, maintain pressures at 1.25 bar (18 psi) in the front and 1.50 bar (22 psi) in the rear.
Ignition & Electrical
The ignition system relies on an NGK CR9E spark plug. To prevent fouling and ensure efficient combustion, the gap must be precisely set between 0.7 mm and 0.8 mm. The electrical system is supported by a compact YTX5L-BS battery, which provides sufficient cranking amps while keeping the center of gravity low.
Verdict
The Suzuki DR 250 S (SG42A) remains a benchmark for mechanical simplicity and engineering foresight. Its blend of oil-cooled durability and lightweight chassis makes it a highly desirable classic for modern dual-sport enthusiasts who value reliability over electronic complexity.