How to Change the Oil in a 2024 KTM 125SX: The MotoSport.com Guide
Shop parts for a 2024 KTM 125SX Dirt Bike.
Regular oil changes are essential for preserving the performance and longevity of your 2024 KTM 125SX. This model features the latest generation two-stroke engine technology, requiring a straightforward but precise oil change procedure. Follow this comprehensive, step-by-step guide tailored specifically for the 2024 KTM 125SX, including necessary tools, tips, and key model-specific callouts to ensure you get the job done right.
Tools and Supplies Needed
- 8mm or 13mm socket or T-handle wrench (check your owner's manual for your drain plug size)
- Torque wrench
- Oil drain pan
- Funnel
- Clean rags
- Magnetic drain plug washer/seal (new, KTM recommends replacement each oil change)
- Engine oil: 800 ml (0.8 L or 0.85 qt) of 10W-40 or 10W-50 motorcycle-specific oil (check your owner's manual to confirm viscosity and type)
- Pliers (to snug up the oil fill cap as suggested by KTM)
- Nitrile gloves (optional, but keeps your hands clean.)
Step-by-Step Oil Change Instructions
-
Warm Up the Bike
Run the engine for a few minutes. This ensures oil drains smoothly by thinning it and suspending particulates in the oil for removal. Note: Be cautious—oil will be hot. -
Position Your Bike & Tools
Place the bike on a level stand. Position your oil drain pan beneath the drain plug to catch all old oil. -
Remove the Oil Fill Cap
Loosen and remove the fill cap. This allows air in and helps the old oil flow out faster and more completely.
On the 2024 125SX, the fill cap is easily accessible on the right-hand clutch cover. -
Remove the Drain Plug
Locate the drain plug beneath the engine (check your manual if unsure), and use the appropriate tool to loosen it. Allow the oil to drain completely.
KTM threads are aluminum, so avoid cross-threading and overtightening.
The 2024 model (and all TBI KTM 2-strokes) have a drain plug torque spec of 20 Nm (14.8 ft-lbs). This spec is conveniently stamped near the plug on your engine case. -
Inspect & Clean the Magnetic Drain Plug
Clean any metallic debris from the drain plug's magnet. A small amount of fine particles is normal after use.
Replace the crush washer/seal with a new one during each change to prevent drips or leaks. -
Reinstall the Drain Plug
Hand-thread the plug to avoid cross-threading, then tighten with a torque wrench to the specified 20 Nm. Never overtighten. -
Fill with Fresh Oil
Insert a clean funnel into the oil fill opening. Pour in 800 ml (0.8 L / 0.85 qt) of your recommended oil. Do not exceed the recommended capacity.
Some riders prefer to add until a slight weep appears at the weep hole/check bolt. If you use this method, replace the check bolt as soon as you see oil weep out and finish topping up to the specification. -
Reinstall the Oil Fill Cap
Thread on the fill cap and, as per KTM's advice, give it a final snug with pliers to ensure it's secure and won't vibrate loose. -
Double-Check for Leaks
Wipe down the engine's underside. Start the bike and let it run for a minute. Inspect the drain plug and oil fill area for leaks. Shut off the engine and recheck the oil level. Top off as necessary. -
Record Your Maintenance
Log the oil change, including mileage/hours and type of oil used, in your maintenance log or app.
2024 KTM 125SX-Specific Callouts and Tips
- Oil Type & Capacity: All 2023+ KTM TBI 2-strokes, including the 125SX, use the exact same oil volume: 800 ml (0.8 L or 0.85 qt) of high-quality, motorcycle-specific oil. Do not overfill.
- Drain Plug Torque Spec: Clearly marked on the case–20 Nm (14.8 ft-lbs). Over-tightening can strip the threads in the aluminum case. Use a proper torque wrench for this step.
- Crush Washer Replacement: Always replace the drain plug washer to minimize the chance of leaks. These are inexpensive and can save significant headaches later.
- Check Bolt (“Weep Hole”) Method: For an accurate fill, some riders use the check bolt method: fill until oil weeps from the check bolt, then reinstall bolt. Though not required by the manual, it helps prevent overfilling.
- Oil Fill Cap Tightening: KTM recommends snugging the fill cap with pliers, not just hand-tightening. This is a specific note and helps prevent the cap from loosening during a ride.
- Compatibility: The oil change procedure and specs are identical for all 2023+ KTM 2-stroke TBI engines, including the XC and SX variants in the 125, 250, and 300 ranges.
- Safe Disposal: Always dispose of used oil at a certified recycling or hazardous waste facility. Never dump oil on the ground or in drains.
MotoSport.com Note
This guide is proprietary to MotoSport.com. For parts, tools, and recommended oils, shop MotoSport.com for everything you need for your 2024 KTM 125SX maintenance. If you encounter issues or are unsure about any step, consult your authorized KTM service center.
Stay safe and enjoy the ride.
Related Shopping Categories
Shop Motor Oil for a 2024 KTM 125SX Dirt Bike.
Shop Oil Filters for a 2024 KTM 125SX Dirt Bike.
Shop Oil Drain Pans for a 2024 KTM 125SX Dirt Bike.
Shop Tools for a 2024 KTM 125SX Dirt Bike.
Shop Oil Fillers and Drain Plugs for a 2024 KTM 125SX Dirt Bike.
Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.