How to Change the Oil in a 1990 KTM 300EXC – A MotoSport.com Guide
Shop [original item] for a 1990 KTM 300EXC Dirt Bike.
Regularly changing the gearbox oil in your 1990 KTM 300EXC is critical for durability and smooth shifting. Follow these detailed steps to keep your legendary 2-stroke running in top condition. Please note: the 300EXC's engine is a pre-mix 2-stroke and uses a separate gearbox (transmission) oil, not a shared oil system. This guide covers the transmission oil change, not the premix (which is gasoline mixed with 2-stroke oil).
Tools and Supplies Needed
- 13mm socket or T-handle
- Flathead screwdriver (if your fill plug requires it)
- Measuring cup (for precise oil volume)
- Drain pan
- Shop rags or paper towels
- Gearbox oil: 20W-
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.