Royal Enfield Thunderbird 350 / Thunderbird 350X — OEM Fluid, Tire Pressure & Maintenance Specs
346cc Air-Cooled Single OHV Pushrod UCE Twinspark · Source: Royal Enfield Thunderbird 350 / Thunderbird 350X (2012–2020) Official Owner’s Manual Maintenance Specifications
According to the Royal Enfield Thunderbird 350 / Thunderbird 350X (2012–2020) Official Owner’s Manual Maintenance Specifications, the 2012–2020 Royal Enfield Thunderbird 350 / Thunderbird 350X (chassis ME3U3T5C) requires 2.3 L (2.43 US qt) of SAE 15W-50 (JASO MA2, API SL (RE Liquid Gun 15W-50)) engine oil for a drain-only change and 2.45 L (2.59 US qt) with filter service (RE 500616 / HF156). Standard solo cold tire pressure is 155 kPa / 1.55 bar / 22 PSI front (90/90-19 M/C 52P) and 210 kPa / 2.10 bar / 30 PSI rear (120/80-18 M/C 62P), paired with 2× Bosch UR5DDC + W7DC spark plug(s) and a 12V 8Ah VRLA / YTX9-BS battery.
Drain only: 2.3 L (2.43 US qt)
R 210 kPa (2.10 bar)
Est. Range: ~680 km (423 mi)
1. Engine Lubrication, Filter & Clutch Specifications
| Clutch Architecture | Wet Multi-Plate Manual Clutch NEVER use JASO MB |
|---|---|
| Recommended Viscosity & Grade | SAE 15W-50 · JASO MA2 · API SL (RE Liquid Gun 15W-50) |
| Oil Volume (Drain / With Filter / Overhaul) |
• Drain only: 2.3 L (2.43 US qt) • With filter/strainer: 2.45 L (2.59 US qt) • Complete dry overhaul: 2.75 L (2.91 US qt) |
| OEM Oil Filter Code & Type | RE 500616 / HF156 |
| Correct Oil Level Check Method | Hold bike upright on level ground 3–5 min after warm shutdown; read crankcase sight glass |
| Oil Drain Bolt Torque | 25 N·m (18.4 lb-ft / 2.55 kgf·m) — Use fresh crush washer |
2. Cold Tire Pressures, Wheels, Ignition & Drivetrain
| Front / Rear OEM Tire Sizes | Front: 90/90-19 M/C 52P · Rear: 120/80-18 M/C 62P (Tubeless) |
|---|---|
| Cold Tire Pressure — Solo Riding |
Front: 155 kPa / 1.55 bar / 22 PSI Rear: 210 kPa / 2.10 bar / 30 PSI |
| Cold Tire Pressure — 2-Up / Loaded Touring |
Front: 165 kPa / 1.65 bar / 24 PSI Rear: 230 kPa / 2.30 bar / 33 PSI |
| OEM Spark Plug & Quantity | Bosch UR5DDC + W7DC × 2 (Gap: 0.7–0.8 mm) |
| OEM Battery Code & Rating | 12V 8Ah VRLA / YTX9-BS (12V 8.0Ah MF AGM) |
| Final Drive Maintenance | 520 Sealed X-Ring Chain — Maintain 25–35 mm slack and clean/lubricate regularly |
| Brake Fluid & Coolant | DOT 4 · Air/Oil-Cooled Engine (No liquid coolant) |
3. Ergonomics, Range & Scheduled Service Intervals
| Displacement · Max Power · Peak Torque | 346 cc · 19.8 hp @ 5,250 rpm · 28 N·m (20.7 lb-ft) @ 4,000 rpm |
|---|---|
| Seat Height & Wet Curb Weight | 775 mm (30.5 in) · 197 kg (434 lbs) |
| Fuel Tank & Est. Real-World Range | 20 L (5.3 US gal) · ~34 km/L → ~680 km (423 mi) |
| OEM Scheduled Maintenance Intervals |
• First Break-In: 500 km • Engine Oil / Filter: 6,000 km / 6,000 km • Air Filter / Spark Plug: 10,000 km / 20,000 km • Valve Clearance Check: 24,000 km |
4. Generation Cutoffs & Real-World Wrenching Gotchas
Model-Year & Chassis Generation Notes
Direct cruiser predecessor to the Meteor 350 boasting a 20 L tank and projector headlamp; the 2018+ 350X introduced factory 9-spoke tubeless alloy wheels.
Oil & Clutch Mechanical Engineering Note
Built for 600+ km tank range on highways, refresh its 2.45 L SAE 15W-50 JASO MA2 sump and HF156 filter every 6,000 km.