KTM 125 DUKE (EURO 5) (2021–2023) — Specs

Identity
Manufacturer: KTM
Model: 125 DUKE (EURO 5)
Category: Naked
Type: Motorcycle
Years: 2021 → 2023
Engine
Displacement (cc): 125
Cylinders: 1
Power (hp): 15
Power (kW): 11
Torque (Nm): 12
Dimensions

Overall length: 2002 mm
Overall width: 786 mm
Overall height: 1090 mm
Wheelbase: 1357 mm
Ground clearance: 165 mm
Weight (kg): 139
Seat height (mm): 810
Tank (L): 13.4
Tires
Front tire: 110/70 R17
Rear tire: 150/60 R17
Front pressure (bar): 2
Rear pressure (bar): 2
Drivetrain
Drive chain: 520 X-ring
Sprockets (front / rear): 14 / 45
Fluids & Filters
Engine oil: SAE10W-40, 15W-50
Engine oil (with filter, L): 1.5
Oil filter: Hiflofiltro HF155
Air filter: Hiflofiltro HFA6303
Coolant (L): 1
Brake fluid: DOT 4
Fuel consumption
Manufacturer / WMTC: 2.5 L/100 km
Real-world range: ~536 km on a full tank (13.4 L)
Note: real-world ±15-30% depending on riding style
Service
Battery: YTX7L-BS
Service interval (km): 6000
Service interval (months): 12
Valve check (km): 12000
Parts and consumables for this motorcycle
Data is gathered with care, but without guarantee. Always confirm critical information with your dealer or workshop.
Service notes
Service interval: every 6,000 km or 12 months, whichever comes first. Valve clearance check every 12,000 km. Valve clearance — intake cold 0.10-0.15 mm, exhaust cold 0.15-0.20 mm. Engine oil: oil grade SAE10W-40, 15W-50, 1.5 L with filter change. Brake fluid: DOT 4. Coolant capacity: 1 L. Chain: 520 X-ring, sprockets 14/45 teeth. Tire pressure: front 2 bar, rear 2 bar (cold). Tire size: front 110/70 R17, rear 150/60 R17. Always confirm critical values with the workshop manual or an authorised dealer.
OEM and quality aftermarket parts that fit this bike. Always confirm with your dealer before ordering.
Engine oil
Spec: SAE 10W-50, 1.0 L (with filter)
- OEM OEM recommended engine oil (SAE 10W-40)
- Premium Motul 7100 4T (100% Synthetic, Ester)
- Premium Motul 5100 4T Technosynthese (Semi-Synthetic)
Which Motul for this bike?
| Motul 7100 4T ✓ | Motul 5100 4T | |
|---|---|---|
| Product | Motul 7100 4T — 100% fully synthetic | Motul 5100 4T — semi-synthetic |
| Best for | Sport, Naked, Adventure (600cc+), track | Standard, Cruiser, Scooter, daily use |
| RPM protection | Excellent — ester base, stable under load | Good — for normal riding conditions |
- Premium Liqui Moly Motorbike 4T
- Standard Repsol Moto Racing 4T (Synthetic)
- Standard Elf Moto 4 Tech (Semi-Synthetic)
- Standard TotalEnergies Quartz Moto 4T
Fully Synthetic vs Semi-Synthetic
| Fully Synthetic | Semi-Synthetic | |
|---|---|---|
| Base oil | 100% chemical synthesis (ester or PAO) | Mineral oil + synthetic additives |
| Heat resistance | Excellent — stable at extreme heat & RPM | Good — suitable for normal temperatures |
| Cold start | Better — reaches engine faster when cold | Good — adequate for normal climates |
| Change interval | Longer (up to 10,000 km) | Shorter (5,000–7,000 km typical) |
| Price | Higher | Lower |
Oil filter
Spec: Hiflofiltro HF155
- Premium Hiflofiltro HF155
- Premium K&N KN-155
Air filter
Spec: Hiflofiltro HFA6303
- Standard Hiflofiltro HFA6303
Spark plug
Spec: NGK LKAR8AI-9, gap 0.8-0.9 mm
- OEM NGK LKAR8AI-9
- Premium NGK LKAR8AI-9
- Standard NGK LKAR8AI-9
Front brake pads
Spec: OEM front pad (EBC equivalent: FA181HH)
- Premium EBC FA181HH
- Standard EBC FA181 (organic)
Rear brake pads
Spec: OEM rear pad (EBC equivalent: FA192HH)
- Premium EBC FA192HH
- Standard EBC FA192 (organic)
Drive chain
Spec: 520 X-ring | Sprockets 14/45 teeth / 520 X-ring
Front sprocket
Spec: 14 teeth
Rear sprocket
Spec: 45 teeth
Front tire
Spec: 110/70 R17, 2.0 bar
- OEM OEM 110/70 R17
Rear tire
Spec: 150/60 R17, 2.0 bar
- OEM OEM 150/60 R17
Battery
Spec: OEM battery: Yuasa YTX7L-BS
- OEM OEM battery: Yuasa YTX5L-BS
- Premium Yuasa YTX5L-BS
Brake fluid
Spec: DOT 4
- Standard TotalEnergies HBF4
Coolant
Spec: 1.00 L coolant capacity
Service interval
Spec: 6 000 km / 12 months
- OEM Engine oil + oil filter change
- OEM Air filter inspection
- OEM Spark plug check
- OEM Brake fluid replacement: every 2 years
Valve check
Spec: 12 000 km
- OEM Intake clearance: cold 0.10-0.15 mm
- OEM Exhaust clearance: cold 0.15-0.20 mm
Suspension
Spec: 43 mm USD fork
- OEM Fork: 43 mm USD fork
