| Component | Specification |
|---|---|
| Model Designation | RE441 (EURO 5) |
| Production Years | 2021–Present |
| Engine Oil | Yamalube 4 (10W-40), JASO MA (1.0 L) |
| Tire Size (F/R) | 110/70-17 / 140/70-17 |
| Spark Plug | NGK CPR8EA-9 |
| Battery | YTZ6V |
A unique engineering highlight of the Yamaha XSR 125 (RE441) is its utilization of the Variable Valve Actuation (VVA) system. While most 125cc machines struggle with a narrow powerband, the XSR 125 employs a solenoid-activated cam profile switch at 7,400 RPM. This allows the engine to maintain high torque at low speeds while maximizing peak horsepower at the top end, a direct technology transfer from Yamaha’s higher-displacement performance lineages.
Technical Powertrain Analysis
The RE441 engine is a liquid-cooled, 4-stroke, SOHC, 4-valve single cylinder. To meet stringent EURO 5 emissions standards, the fuel injection mapping and catalytic converter systems are highly optimized. For maximum longevity, MotoSpecsLab recommends the use of Yamalube 4 (10W-40). The system requires exactly 1.0 liter for a standard oil change. Ensure the oil meets JASO MA standards to prevent clutch slippage in the wet-plate system.
Chassis and Road Contact
The XSR 125 features a premium Deltabox frame, providing significantly more rigidity than the tubular frames found on competitors. This chassis is paired with 17-inch wheels. Maintaining correct tire pressure is critical for the bike’s nimble handling characteristics:
- Front (110/70-17 M/C 54S): 2.0 bar (29 psi)
- Rear (140/70-17 M/C 66S): 2.3 bar (33 psi)
Electrical and Ignition System
The electrical system is powered by a YTZ6V battery. Given the Euro 5 electronics and LED lighting suite, maintaining a healthy voltage is paramount. The ignition system utilizes an NGK CPR8EA-9 spark plug. We recommend inspecting the plug gap every 6,000 km to ensure optimal combustion efficiency and throttle response.
Maintenance Summary
The XSR 125 is a robust machine, but its high-revving nature demands precision. Regular chain tensioning, combined with the aforementioned fluid and pressure checks, ensures the RE441 remains the benchmark for the premium 125cc neo-retro segment.