KTM 390 Duke (LC4c) — OEM Fluid, Tire Pressure & Maintenance Specs
373cc / 399cc High-Compression Liquid-Cooled Single DOHC (Wet PASC Slipper Clutch) · Source: KTM 390 Duke Official Owner’s Manual Maintenance Specifications
According to the KTM 390 Duke Official Owner’s Manual Maintenance Specifications, the 2017–Present KTM 390 Duke (LC4c) (chassis 938/948 (LC4c)) requires 1.5 L (1.59 US qt) of SAE 15W-50 (JASO MA2, API SL/SN Full Synthetic) engine oil for a drain-only change and 1.7 L (1.80 US qt) with filter service (90138015000 / HF155 + Dual Mesh Screens). Standard solo cold tire pressure is 200 kPa / 2.00 bar / 29 PSI front (110/70ZR17 M/C 54W) and 200 kPa / 2.00 bar / 29 PSI rear (150/60ZR17 M/C 66W), paired with 1× NGK LKAR8AI-9 spark plug(s) and a YTX9-BS / ETZ9-BS battery.
Drain only: 1.5 L (1.59 US qt)
R 200 kPa (2.00 bar)
Est. Range: ~420 km (261 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/SN Full Synthetic |
| Oil Volume (Drain / With Filter / Overhaul) |
• Drain only: 1.5 L (1.59 US qt) • With filter/strainer: 1.7 L (1.80 US qt) • Complete dry overhaul: 1.9 L (2.01 US qt) |
| OEM Oil Filter Code & Type | 90138015000 / HF155 + Dual Mesh Screens |
| 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 | 15 N·m (11.1 lb-ft / 1.53 kgf·m) — Use fresh crush washer |
2. Cold Tire Pressures, Wheels, Ignition & Drivetrain
| Front / Rear OEM Tire Sizes | Front: 110/70ZR17 M/C 54W · Rear: 150/60ZR17 M/C 66W (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: 220 kPa / 2.20 bar / 32 PSI Rear: 250 kPa / 2.50 bar / 36 PSI |
| OEM Spark Plug & Quantity | NGK LKAR8AI-9 × 1 (Gap: 0.8–0.9 mm) |
| OEM Battery Code & Rating | YTX9-BS / ETZ9-BS (12V 8.0Ah MF AGM) |
| Final Drive Maintenance | 520 X-Ring Chain — Measure per KTM swingarm slider clearance chart |
| Brake Fluid & Coolant | DOT 4 · Motorex M3.0 Ready-to-Use Silicate-Free Coolant |
3. Ergonomics, Range & Scheduled Service Intervals
| Displacement · Max Power · Peak Torque | 399 cc · 44.9 hp @ 8,500 rpm · 39 N·m (28.8 lb-ft) @ 7,000 rpm |
|---|---|
| Seat Height & Wet Curb Weight | 820 mm (32.3 in) · 165 kg (364 lbs) |
| Fuel Tank & Est. Real-World Range | 15 L (4.0 US gal) · ~28 km/L → ~420 km (261 mi) |
| OEM Scheduled Maintenance Intervals |
• First Break-In: 1,000 km • Engine Oil / Filter: 7,500 km / 7,500 km • Air Filter / Spark Plug: 15,000 km / 15,000 km • Valve Clearance Check: 15,000 km |
4. Generation Cutoffs & Real-World Wrenching Gotchas
Model-Year & Chassis Generation Notes
Both Gen 2 (2017–2023, 373cc) and Gen 3 (2024+ LC4c, 399cc) require full-synthetic SAE 15W-50 JASO MA2 oil and use a replaceable paper cartridge alongside cleanable mesh evacuate screens.
Oil & Clutch Mechanical Engineering Note
High cylinder head temperatures in KTM’s big-bore single will shear thin 10W-30 oil; stick strictly to full-synthetic SAE 15W-50 JASO MA2 (Motorex Formula/Power Synt 4T spec) to protect cam followers and timing tensioner pressure.
Garage Wrenching Gotchas
- Pull and clean the cylindrical mesh oil screens with brake cleaner at every oil change, and respect the low ~15 N·m torque on the side drain screen plug.
- KTM specifies checking the sight glass at full operating temperature (1 minute after shutting down on level ground)—cold checks read artificially low.
5. Frequently Asked Questions (FAQ)
Why does the KTM 390 Duke require SAE 15W-50 instead of 10W-40?
Yes—KTM’s high-strung single runs hot and relies on high-temperature film thickness; SAE 15W-50 JASO MA2 full synthetic prevents oil pressure drop at idle in summer traffic.
How much oil does the KTM 390 Duke take with filter replacement?
Service refill with paper filter and screen cleaning is approximately 1.7 L (1.8 US qt), verified warm in the sight glass.
What is the recommended cold tire pressure for the 390 Duke?
Solo agile street baseline is 200 kPa (29 PSI) front and rear, rising to 220 kPa (32 PSI) front / 250 kPa (36 PSI) rear for touring or pillion loads.