| Component | Specification |
|---|---|
| Engine | 644cc Air-cooled Single Cylinder (RFVC) |
| Oil Type | SAE 10W-40 (API SG/JASO MA) |
| Oil Capacity | 2.1 L (Change) / 2.5 L (Dry Fill) |
| Tires (F/R) | 100/90-19 57H / 120/90-17 64H |
| Spark Plug | NGK DPR8EA-9 (0.8–0.9 mm gap) |
| Battery | YTX9-BS |
A unique engineering highlight of the Honda FX 650 Vigor (RD09) is its production origin; unlike many of its Japanese-built contemporaries, the Vigor was manufactured at the Honda Montesa factory in Spain. It utilized the legendary 644cc single-cylinder engine featuring the Radial Four Valve Combustion (RFVC) chamber—a design originally developed for off-road dominance—but re-tuned for the ‘Urban Scrambler’ market with a softer cam profile and a focus on low-to-mid range torque.
Technical Review: The RD09 Philosophy
The FX 650 Vigor was Honda’s strategic response to the growing demand for versatile city bikes in the late 90s. By stripping away the heavy fairings of the NX650 Dominator and adding a 19-inch front wheel (compared to the typical 21-inch off-road wheel), Honda created a motorcycle with superior agility in traffic and a lower seat height. The steel cradle frame provides a stable platform, while the air-cooled engine remains one of the most reliable ‘thumpers’ ever produced, provided thermal management is respected.
Maintenance Guide & Essential Specifications
Lubrication and Fluids
The RFVC engine is oil-cooled and relies heavily on high-quality lubricant to dissipate heat from the cylinder head. Always use SAE 10W-40 meeting JASO MA standards to ensure the wet clutch performs correctly. A standard oil change requires 2.1 liters, while a dry engine (after rebuild) requires 2.5 liters. Given the air-cooled nature, MotoSpecsLab recommends changing the oil every 3,000–4,000 km for optimal longevity.
Tires and Pressure
The Vigor uses a specific wheel combination to balance stability and flickability:
- Front: 100/90-19 57H (2.0 bar / 29 psi)
- Rear: 120/90-17 64H (2.0 bar / 29 psi solo; 2.5 bar / 36 psi with passenger)
Ignition and Electrical
The electrical system is centered around a YTX9-BS battery. For the ignition system, the NGK DPR8EA-9 is the standard plug. Ensure the electrode gap is precisely 0.8–0.9 mm to prevent misfires and ensure efficient combustion in the radial chamber.
Expert Verdict
The Honda FX 650 Vigor remains a cult favorite for its simplicity and mechanical character. While it lacks the high-speed touring capability of modern adventure bikes, its robust construction and ease of maintenance make it an ideal candidate for custom builds (trackers/scramblers) or as a reliable daily commuter for those who appreciate the ‘thumper’ experience.
Frequently Asked Questions
Is the FX 650 Vigor suitable for beginners?
Yes, its manageable power delivery and upright ergonomics make it an excellent choice for A2 license holders and novice riders.
How does the Vigor differ from the SLR 650?
The Vigor is the successor to the SLR 650, featuring updated styling (specifically the fuel tank and seat) and a more comprehensive instrument cluster, though they share the same engine and frame.