Honda GB350S / CB350RS (NC59) — OEM Fluid, Tire Pressure & Maintenance Specs
348cc Air-Cooled Single SOHC 2V Long-Stroke + 17-Inch Rear Wheel · Source: Honda GB350S / CB350RS (NC59) (2021–Present) Official Owner’s Manual Maintenance Specifications
According to the Honda GB350S / CB350RS (NC59) (2021–Present) Official Owner’s Manual Maintenance Specifications, the 2021–Present Honda GB350S / CB350RS (NC59) (chassis NC59) requires 2 L (2.11 US qt) of SAE 10W-30 (JASO MA, API SJ or higher) engine oil for a drain-only change and 2.1 L (2.22 US qt) with filter service (15412-MGS-D21 / HF117). Standard solo cold tire pressure is 200 kPa / 2.00 bar / 29 PSI front (100/90-19M/C 57H) and 200 kPa / 2.00 bar / 29 PSI rear (150/70R17M/C 69H), paired with 1× NGK MR7E-9 spark plug(s) and a YTZ8V / YTX7L-BS battery.
Drain only: 2 L (2.11 US qt)
R 200 kPa (2.00 bar)
Est. Range: ~585 km (364 mi)
1. Engine Lubrication, Filter & Clutch Specifications
| Clutch Architecture | Wet Multi-Plate Manual Clutch NEVER use JASO MB |
|---|---|
| Recommended Viscosity & Grade | SAE 10W-30 (Alt: SAE 10W-40) · JASO MA · API SJ or higher |
| Oil Volume (Drain / With Filter / Overhaul) |
• Drain only: 2 L (2.11 US qt) • With filter/strainer: 2.1 L (2.22 US qt) • Complete dry overhaul: 2.5 L (2.64 US qt) |
| OEM Oil Filter Code & Type | 15412-MGS-D21 / HF117 |
| Correct Oil Level Check Method | Hold upright on level ground; rest dipstick UNTHREADED on filler neck (do NOT screw in) |
| Oil Drain Bolt Torque | 24 N·m (17.7 lb-ft / 2.45 kgf·m) — Use fresh crush washer |
2. Cold Tire Pressures, Wheels, Ignition & Drivetrain
| Front / Rear OEM Tire Sizes | Front: 100/90-19M/C 57H · Rear: 150/70R17M/C 69H (Tubeless) |
|---|---|
| Cold Tire Pressure — Solo Riding |
Front: 200 kPa / 2.00 bar / 29 PSI Rear: 200 kPa / 2.00 bar / 29 PSI |
| Cold Tire Pressure — 2-Up / Loaded Touring |
Front: 200 kPa / 2.00 bar / 29 PSI Rear: 225 kPa / 2.25 bar / 33 PSI |
| OEM Spark Plug & Quantity | NGK MR7E-9 × 1 (Gap: 0.8–0.9 mm) |
| OEM Battery Code & Rating | YTZ8V / YTX7L-BS (12V 7.0Ah MF AGM) |
| Final Drive Maintenance | 520 Sealed O/X-Ring Chain — Maintain 25–35 mm slack and lube every 800–1,000 km |
| Brake Fluid & Coolant | DOT 4 · Air-Cooled Engine (No liquid coolant) |
3. Ergonomics, Range & Scheduled Service Intervals
| Displacement · Max Power · Peak Torque | 348 cc · 20.8 hp @ 5,500 rpm · 29 N·m (21.4 lb-ft) @ 3,000 rpm |
|---|---|
| Seat Height & Wet Curb Weight | 800 mm (31.5 in) · 178 kg (392 lbs) |
| Fuel Tank & Est. Real-World Range | 15 L (4.0 US gal) · ~39 km/L → ~585 km (364 mi) |
| OEM Scheduled Maintenance Intervals |
• First Break-In: 1,000 km • Engine Oil / Filter: 12,000 km / 12,000 km • Air Filter / Spark Plug: 18,000 km / 24,000 km • Valve Clearance Check: 24,000 km |
4. Generation Cutoffs & Real-World Wrenching Gotchas
Model-Year & Chassis Generation Notes
Sportier roadster variant of the NC59 GB350 swapping the 18-inch rear wheel for a wider 150/70R17 radial tire, fork gaiters, setback pegs, and a blacked-out upswept muffler.
Oil & Clutch Mechanical Engineering Note
Honda liquid-cooled DOHC single (CB/CBR/CRF/Rebel 250–300) using internal paper element 15410-KYJ-902 (observe OUT-SIDE mark!) and SAE 10W-30 JASO MA.