How to Change the Oil in a 1983 Suzuki RM250: The Complete MotoSport.com Guide

Shop parts for a 1983 Suzuki RM250 Dirt Bike.

Changing the transmission oil in your 1983 Suzuki RM250 is a key maintenance step that keeps your dirt bike performing at its best and prolongs the life of the transmission. Some unique points about this particular model and year will be highlighted throughout the guide. The process is straightforward, requiring just a few tools and about half an hour of your time.

Tools and Materials Needed

  • Socket wrench set (including correct size for drain plug, usually 12mm or 14mm for vintage Suzuki)
  • Allen key set (for check bolt access)
  • Drain pan
  • Funnel
  • Clean shop rags
  • New transmission oil (Recommended: SAE 20W/40 for 1983 RM250 transmission only–do not use this oil premixed with gas for 2-stroke engine lubrication)
  • Torque wrench
  • Gloves and safety glasses

Oil Specs and Capacity Specifics for 1983 RM250

  • Transmission oil only: SAE 20W/40 is strongly recommended
  • Capacity when changing oil: 900 ml (1.9 US pint – 1.6 Imp pint)
  • Capacity after overhaul: 1,000 ml (2.1 US pint – 1.8 Imp pint)
  • Engine uses pre-mix fuel; only the transmission oil is changed

Note: Never mix brands or types of oil in the transmission. Always perform the oil change with the engine off and cool to prevent burns and accidental injury. Place the bike on a level surface and hold it upright for accurate draining and filling.

Step-by-Step Guide to Changing the Oil

1. Warm Up the Engine

  • Briefly start and idle the bike until the engine and transmission are warm but not hot. This helps thin out the oil, so it drains completely from the gearbox.
  • Shut off the engine and allow the bike to cool just enough for safe handling.

2. Prepare the Bike and Work Area

  • Stand the bike on a level surface and use a stand if available to hold it upright.
  • Lay out all tools and supplies within reach.
  • Put on gloves and safety glasses to protect against oil splashes.

3. Locate the Drain Plug

  • The oil drain plug is found on the bottom of the transmission case, underneath the bike.
  • Place the drain pan directly beneath the drain plug to catch oil.

4. Drain the Old Oil

  • Unscrew the oil filler cap on top of the transmission to allow air flow.
  • Use a socket wrench to remove the drain plug at the bottom of the case.
  • Allow the oil to drain completely. It may help to gently tilt the bike if safely supported, but keep it upright for the best results.
  • Inspect the drain plug for metal shavings or debris, which could indicate excessive transmission wear.

5. Replace and Tighten the Drain Plug

  • Once the oil is finished draining, wipe the drain area with a clean rag.
  • Reinstall the oil drain plug and torque it to 21 N·m (15.0 lb-ft) to ensure a leak-free seal.

6. Add New Transmission Oil

  • Using a funnel, slowly pour the correct volume (900 ml) of SAE 20W/40 transmission oil into the oil filler opening.
  • Allow a few seconds for the oil to settle in the transmission gears and bearings.

7. Check Oil Level & Reinstall the Cap

  • Optional but very helpful: On the RM250, there may be an oil check bolt found behind the wire near the chain guard, accessible with an Allen key. Remove this for a level check after filling; oil should seep gently from this bolt hole when the correct level is reached.
  • Wipe up any spills and reinstall both the oil check bolt and the filler cap securely.

8. Inspect and Test

  • Start the engine and let it idle for a couple of minutes, then shut it off and check for leaks around the drain plug and filler cap.
  • After a short ride, check the oil level again and top up if needed.

Special Notes and Callouts for the 1983 RM250

  • This year/model does not use engine oil for combustion; engine lubrication is handled by mixing a quality 2-stroke oil into the fuel. This procedure refreshes only the transmission oil.
  • Some older Suzuki models may have a hidden oil check bolt behind wiring or near the front sprocket/chain guard—check your frame and remove the chain guard if necessary to access it, as per rider tips and video guides.
  • Avoid overfilling and always use the correct oil type and quantity to prevent transmission issues.
  • Keep records of each oil change to monitor intervals and usage conditions.

Conclusion

With the right tools and close attention to capacity and oil specifications, changing the oil in your vintage 1983 Suzuki RM250 is a simple way to ensure a long life and maximum performance from your dirt bike. For more maintenance tips and genuine Suzuki parts, always trust your friends at MotoSport.com. Ride safe.

Related Shopping Categories

Shop Motor Oil for a 1983 Suzuki RM250 Dirt Bike.

Shop Oil Filters for a 1983 Suzuki RM250 Dirt Bike.

Shop Oil Drain Pans for a 1983 Suzuki RM250 Dirt Bike.

Shop Tools for a 1983 Suzuki RM250 Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 1983 Suzuki RM250 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.