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KTM 125 SX

Maintenance specs for 1 variant of the KTM 125 SX — from 1998 to 2026.

19982026 KTM 125 SX

124.8cc Single-Cylinder 2-Stroke Liquid-Cooled MX (125 SX) · Chain

30 hp / lb-ft

Transmission

Type6-Speed Manual (gearbox oil)
FluidMotorex Top Speed 4T 15W-50
Drain & fill0.64 qt

Coolant

TypeMotorex Anti-Freeze (50/50 premix)
Capacity1.1 qt
Shop coolant

Brake Fluid

TypeDOT 4
Shop DOT 4

Fuel

Tank1.9 gal
TypePremium 91 + 2-stroke oil premix

Tires

Front80/100-21
Rear100/90-19
Pressure (front)15 PSI
Pressure (rear)15 PSI

Service Intervals

Trans service300 mi
Coolant flush1,500 mi
Spark plugs600 mi
Air filter150 mi
Drive belt600 mi