| Specification | Detail |
|---|---|
| Production Years | 2015 – 2020 |
| Engine Type | 279cc Single-cylinder, 4-stroke, Liquid-cooled |
| Oil Specification | SAE 10W-30 (API SG+ / JASO MB) |
| Tire Size | F: 110/70-16 | R: 130/70-16 |
| Battery Type | YTZ12S (Maintenance Free) |
| Spark Plug | NGK LMAR8A-9 (Gap: 0.8-0.9mm) |
A unique engineering highlight of the Honda SH 300 I – NF05B is its status as the first high-performance scooter to successfully integrate a Euro 4 compliant powertrain while maintaining the iconic “Step-Through” flat floorboard. Achieving the necessary frame rigidity for a 300cc engine without a central backbone is a testament to Honda’s advanced steel-tube underbone chassis design, which provides high-speed stability without sacrificing urban utility.
Technical Review: The NF05B Evolution
Released in 2015, the NF05B generation refined the SH 300 I formula by focusing on efficiency and torque delivery. The engine was re-engineered to provide better low-to-mid range response, essential for city filtering. Unlike many of its competitors that moved to 14-inch or 15-inch wheels, Honda retained the 16-inch diameter, ensuring the SH 300 I remains the gold standard for stability over uneven cobblestones and potholes.
Maintenance Guide & Fluid Specifications
Engine Lubrication
The NF05B is particularly sensitive to oil selection. It requires SAE 10W-30 oil. Crucially, it must meet the JASO MB standard rather than the more common JASO MA. JASO MB is a low-friction oil formulated specifically for scooters with dry-clutch CVTs. Using JASO MA will not cause immediate damage but will lead to decreased fuel efficiency and increased internal drag.
- Drain only: 1.2 Liters
- Oil & Filter change: 1.4 Liters
- Total capacity (Dry): 1.7 Liters
Ignition and Electrical
The ignition system utilizes a long-reach NGK LMAR8A-9 spark plug. Given the high-compression nature of the 279cc engine, maintaining the precise gap of 0.8-0.9mm is vital for cold-start reliability and fuel economy. The electrical system is anchored by the YTZ12S battery, which provides the high CCA (Cold Cranking Amps) required for the SH’s automatic decompression system.
Chassis and Safety: Tires & Pressures
The 16-inch wheels are the defining characteristic of the NF05B’s handling. Proper inflation is critical to prevent “weaving” at high speeds:
- Front (110/70-16 M/C 52P): 2.00 bar (29 psi)
- Rear (130/70-16 M/C 61P): 2.25 bar (33 psi) for solo riding; increase to 2.80 bar (41 psi) when carrying a passenger or heavy top-box loads.
Expert Verdict
The Honda SH 300 I (NF05B) remains a pinnacle of Japanese functional design. For the owner, adherence to the JASO MB oil specification and strict tire pressure monitoring are the two most important factors in preserving the machine’s legendary reliability and handling precision. It is not merely a commuter; it is a precision-engineered tool for the modern urban environment.