How to Change the Oil in a 1998 Suzuki RMX250: A Complete Guide

Shop parts for a 1998 Suzuki RMX250 Dirt Bike.

Keeping your 1998 Suzuki RMX250 running smoothly means performing regular oil changes. This guide, proprietary to MotoSport.com, explains all the steps, tools required, and special model-specific considerations to ensure your RMX250 transmsission and engine stay in peak condition.

Tools and Supplies Needed

  • 10mm and 12mm sockets or wrenches (for drain plug and filler cap)
  • Allen key set (for the oil check bolt, as needed)
  • Measuring cup (such as a Ratio Rite, for precise oil measuring)
  • Oil drain pan (low-profile is recommended)
  • Shop rags or towels
  • New crush washer (optional, for the drain bolt)
  • Good quality SAE 10W/40 multi-grade motor oil (classified SF or SG API)
  • Torque wrench
  • Gloves (optional, for keeping hands clean)

Recommended Oil and Capacity

  • Type: SAE 10W40 multigrade engine oil, SF or SG classified (API)
  • Volume (oil change): 650 ml
  • Volume (after overhaul): 750 ml
  • Check owner’s manual for any alternative grade if frequently riding in extreme temperatures.

Steps to Change the Oil on a 1998 Suzuki RMX250

  1. Warm Up the Engine
    • Start the bike and let it idle for 2-3 minutes. This thins the oil, ensuring a more complete drain.
  2. Stabilize the Bike
    • Turn the engine off. Place the bike on a level surface, using a stand to keep it upright and vertical.
  3. Locate Filler Cap and Drain Plug
    • Remove the filler cap from the top of the transmission/bottom end of the engine. This allows air in and oil to flow out more freely.
    • The drain plug is located on the bottom of the engine. Refer to your manual or look for the bolt at the lowest point on the right side case .
  4. Drain the Old Oil
    • Position your drain pan beneath the drain plug. Carefully loosen and remove the plug using a 12mm wrench or socket.
    • Allow the oil to fully drain. Be patient—tipping the bike slightly side-to-side can help expel trapped oil.
  5. Inspect and Replace Crush Washer
    • Check the condition of the crush washer on the drain bolt. Replace it if it’s damaged or excessively flattened to prevent leaks.
  6. Reinstall and Torque Drain Plug
    • Wipe off any oil around the drain hole. Reinstall the plug, tightening to 21 Nm (15 lb-ft) using a torque wrench .
  7. Add New Oil
    • Use a clean measuring cup to carefully pour in 650 ml (0.7 US/Imperial pints) of fresh SAE 10W/40 oil through the filler opening .
  8. Check the Oil Level
    • The oil check bolt is behind some wiring and the chain guard; remove the guard and gently move any wires aside to reach the bolt using an Allen key .
    • With the bike upright, loosen the check bolt. If oil seeps out, the level is correct. If not, add oil in small increments until it does.
  9. Reinstall Filler Cap and Oil Check Bolt
    • Tighten both securely by hand, then give a final snug using the correct tool.
  10. Run Engine and Recheck Oil
    • Start the bike and let it idle for a few minutes, then turn it off. Wait a minute, then double-check the oil level with the check bolt and top up if necessary .
  11. Dispose of Used Oil Responsibly
    • Take the oil to a recycling center or auto shop following local regulations.

Special 1998 RMX250 Owner Call-Outs

  • Oil Check Bolt Location: Behind wiring and chain guard, easily missed if you’ve never changed oil on this model .
  • Chain and O-Ring Caution: When servicing the chain during oil changes, use only kerosene for cleaning. Never use gasoline or harsh solvents, as these will damage the “O-ring” seals .
  • Crush Washer: Always inspect and, if necessary, replace the drain plug washer to prevent leaks.
  • Oil Specification: Only use specified SF or SG class oil to avoid damaging the transmission and clutch. Avoid using “energy conserving” oils.

Conclusion

Changing the oil on your 1998 Suzuki RMX250 is a straightforward process, but attention to detail and the right technique keeps your bike dependable and ready for the next ride. MotoSport.com offers all genuine parts and premium SAE 10W/40 oil you need to make every change easy and reliable. Perform this maintenance every 10–15 hours of riding or after any deep water crossings, and your RMX250 will deliver legendary Suzuki two-stroke performance ride after ride.

Related Shopping Categories

Shop Motor Oil for a 1998 Suzuki RMX250 Dirt Bike.

Shop Oil Filters for a 1998 Suzuki RMX250 Dirt Bike.

Shop Oil Drain Pans for a 1998 Suzuki RMX250 Dirt Bike.

Shop Tools for a 1998 Suzuki RMX250 Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 1998 Suzuki RMX250 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.