KTM 125 Duke (LC4c) — OEM Fluid, Tire Pressure & Maintenance Specs
124.9cc Liquid-Cooled Single 4-Valve (Full-Size Trellis Chassis) · Source: KTM 125 Duke (LC4c) (2017–Present) Official Owner’s Manual Maintenance Specifications
According to the KTM 125 Duke (LC4c) (2017–Present) Official Owner’s Manual Maintenance Specifications, the 2017–Present KTM 125 Duke (LC4c) (chassis VBKJPA40/LC4c-125) requires 1.3 L (1.37 US qt) of SAE 15W-50 (JASO MA2, Motorex Formula / Power Synt 4T 15W-50) engine oil for a drain-only change and 1.5 L (1.59 US qt) with filter service (90138015000 / HF155). Standard solo cold tire pressure is 200 kPa / 2.00 bar / 29 PSI front (110/70 R17) and 200 kPa / 2.00 bar / 29 PSI rear (150/60 R17), paired with 1× Bosch VR6NEU / NGK LKAR8AI-9 spark plug(s) and a YTX9-BS / ETZ9-BS battery.
Drain only: 1.3 L (1.37 US qt)
R 200 kPa (2.00 bar)
Est. Range: ~623 km (387 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 · Motorex Formula / Power Synt 4T 15W-50 |
| Oil Volume (Drain / With Filter / Overhaul) |
• Drain only: 1.3 L (1.37 US qt) • With filter/strainer: 1.5 L (1.59 US qt) • Complete dry overhaul: 1.7 L (1.80 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 | 20 N·m (14.8 lb-ft / 2.04 kgf·m) — Use fresh crush washer |
2. Cold Tire Pressures, Wheels, Ignition & Drivetrain
| Front / Rear OEM Tire Sizes | Front: 110/70 R17 · Rear: 150/60 R17 (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 / 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 Sealed X-Ring Chain — Maintain 25–35 mm slack and clean/lubricate regularly |
| Brake Fluid & Coolant | DOT 4 · OAT ethylene-glycol coolant for aluminum radiators (50:50 premix) |
3. Ergonomics, Range & Scheduled Service Intervals
| Displacement · Max Power · Peak Torque | 125 cc · 15 hp @ 10,000 rpm · 12 N·m (8.9 lb-ft) @ 7,500 rpm |
|---|---|
| Seat Height & Wet Curb Weight | 800 mm (31.5 in) · 154 kg (340 lbs) |
| Fuel Tank & Est. Real-World Range | 15 L (4.0 US gal) · ~41.5 km/L → ~623 km (387 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
Shares its full-size trellis chassis, 43 mm WP APEX USD forks, ByBre radial brakes, and TFT dash with the 390 Duke; redesigned in 2024 onto the Gen 3 LC4c platform.
Oil & Clutch Mechanical Engineering Note
Because 125cc riders spend extended time pinned at 8,000–10,000 rpm, run full-synthetic SAE 15W-50 JASO MA2 (1.5 L) and clean the crankcase screen at every change.
Garage Wrenching Gotchas
- Install the paper oil filter (90138015000 / HF155) in the exact manual orientation—inserting it backwards starves upper cylinder-head oil flow immediately.
- Over-tightening the 520 chain binds suspension travel and ruins the countershaft oil seal; always measure chain deflection at the swingarm guide window.
5. Frequently Asked Questions (FAQ)
What oil volume, JASO grade, and oil filter code does the KTM 125 Duke (LC4c) (2017–Present) require?
Because its wet multi-plate clutch shares engine oil with the gearbox, run SAE 15W-50 (JASO MA2) at 1.3 L (1.37 US qt) drain-only and 1.5 L (1.59 US qt) with filter (90138015000 / HF155).
How do you accurately check the oil level on the 125 Duke (LC4c), and what are its service intervals?
Hold the motorcycle dead-vertical on level ground 2–3 minutes after warm shutdown and verify the oil sits mid-way between the Upper and Lower marks in the crankcase sight glass—never on the sidestand. Torque the drain plug to 20 N·m with a new crush washer. Factory oil change intervals are every 7,500 km, with valve clearance inspection every 15,000 km.
What are the cold tire pressures, puncture repair type, seat height, and range of the 125 Duke (LC4c)?
Fitted with 110/70 R17 front and 150/60 R17 rear tubeless rims (compatible with roadside plug kits), set cold tire pressures to 29 / 29 PSI (200/200 kPa) solo or 29 / 32 PSI loaded. Seat height is 800 mm (31.5 in) at 154 kg wet weight, delivering ~623 km per 15 L tank.