KTM RC 390 — OEM Fluid, Tire Pressure & Maintenance Specs
373.2cc Liquid-Cooled Single-Cylinder DOHC 4-Valve (DLC Finger Followers · PASC Slipper Clutch) · Source: KTM RC 390 (Gen 2 Chassis) Official Owner’s Manual Maintenance Specifications
According to the KTM RC 390 (Gen 2 Chassis) Official Owner’s Manual Maintenance Specifications, the 2022–Present KTM RC 390 (chassis VBKJYA40/JY) requires 1.55 L (1.64 US qt) of SAE 15W-50 (JASO MA2, API SN Fully Synthetic (Motorex Formula 4T 15W-50)) engine oil for a drain-only change and 1.7 L (1.80 US qt) with filter service (90138015000 / HF155). Standard solo cold tire pressure is 200 kPa / 2.00 bar / 29 PSI front (110/70 ZR17 M/C 54W) and 200 kPa / 2.00 bar / 29 PSI rear (150/60 ZR17 M/C 66W), paired with 1× Bosch VR6NEU spark plug(s) and a ETZ9-BS / YTX9-BS battery.
Drain only: 1.55 L (1.64 US qt)
R 200 kPa (2.00 bar)
Est. Range: ~377 km (234 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 SN Fully Synthetic (Motorex Formula 4T 15W-50) |
| Oil Volume (Drain / With Filter / Overhaul) |
• Drain only: 1.55 L (1.64 US qt) • With filter/strainer: 1.7 L (1.80 US qt) • Complete dry overhaul: 1.85 L (1.95 US qt) |
| OEM Oil Filter Code & Type | 90138015000 / HF155 |
| 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: 110/70 ZR17 M/C 54W · Rear: 150/60 ZR17 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: 200 kPa / 2.00 bar / 29 PSI Rear: 220 kPa / 2.20 bar / 32 PSI |
| OEM Spark Plug & Quantity | Bosch VR6NEU × 1 (Gap: 1.0 mm) |
| OEM Battery Code & Rating | ETZ9-BS / YTX9-BS (12V 8.0Ah Sealed MF AGM) |
| Final Drive Maintenance | 520 X-Ring Sealed Chain (15T/45T, 112 links) — KTM swingarm guide clearance spec |
| Brake Fluid & Coolant | DOT 4 or DOT 5.1 · Motorex Coolant M3.0 Silicate-Free Premix (~1.2 L) |
3. Ergonomics, Range & Scheduled Service Intervals
| Displacement · Max Power · Peak Torque | 373 cc · 43.5 hp @ 9,000 rpm · 37 N·m (27.3 lb-ft) @ 7,000 rpm |
|---|---|
| Seat Height & Wet Curb Weight | 824 mm (32.4 in) · 164 kg (362 lbs) |
| Fuel Tank & Est. Real-World Range | 13.7 L (3.6 US gal) · ~27.5 km/L → ~377 km (234 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
Redesigned from the ground up for 2022+, the Gen 2 RC 390 introduced ultra-light 5-spoke Bionic wheels (-3.4 kg unsprung mass), a larger 13.7 L fuel tank (up from 9.5 L), WP APEX adjustable forks, and IMU Cornering ABS/MTC over the 2014–2021 first generation.
Oil & Clutch Mechanical Engineering Note
Running a high 12.6:1 compression ratio in a compact 1.7 L single-cylinder sump, KTM strictly requires full-synthetic SAE 15W-50 JASO MA2 oil—thinner 10W-30 or 10W-40 grades thin out prematurely in summer traffic and starve the hydraulic cam-chain tensioner.
Garage Wrenching Gotchas
- Alongside the right-side paper filter (90138015000), clean BOTH plastic/mesh oil screens at the bottom/left crankcase—and torque the drain/screen plugs gently to 15 N·m so you never crack the thin aluminum boss.
- Factory cold street tire pressure is just 200 kPa (2.0 bar / 29 PSI) front and 200 kPa (29 PSI) rear solo—inflating this 164 kg featherweight to 36/42 PSI destroys front-end feel.
5. Frequently Asked Questions (FAQ)
How much oil does the KTM RC 390 hold and how often should I change it?
Refill with the 90138015000 paper filter and cleaned mesh screens is 1.70 L (1.80 US qt) of SAE 15W-50 JASO MA2 synthetic oil; manual interval is 7,500 km, or 3,000–4,000 km for spirited canyon/track riders.
Should KTM RC 390 oil level be checked cold or warm?
Always check at full operating temperature: shut the warm engine off, wait 1 minute with the bike vertical on level ground, and verify oil sits near the upper mark of the sight glass.
How much farther can the 2022+ RC 390 ride on a tank compared to older models?
Fuel capacity grew from 9.5 L to 13.7 L (3.62 US gal), stretching real-world backroad range past 330–360 km per fill-up.