How to Change the Oil in a 1979 Suzuki RM80: A Complete GuideShop parts for a 1979 Suzuki RM80 Dirt Bike.

Changing the oil in your 1979 Suzuki RM80 is essential for maintenance, performance, and longevity. This guide, proprietary to MotoSport.com, walks you through every step with specific tips for this vintage dirt bike.

Tools and Supplies You'll Need

  • 10mm and 21mm sockets or appropriately sized wrenches
  • Oil drain pan (capacity at least 2 quarts)
  • Funnel
  • Clean rags or shop towels
  • Replacement transmission oil - SAE 10W-40, API SG/SH/SJ/SL/SM/SN with JASO MA/MA1/MA2
  • Measuring cup or graduated container (minimum 700ml capacity)
  • Latex or nitrile gloves (recommended)
  • Torque wrench (for drain and filler bolts)

Preparation Steps

  • Make sure the RM80 is parked on level ground and is cool to the touch before you start .
  • Gather all tools and oil supplies in a well-ventilated area.

Step-by-Step Oil Change Procedure

  1. Warm Up the Engine
    Start the bike and let it idle for 2-3 minutes to allow the oil to flow easily. Turn it off and let it sit for a few minutes so the engine is not dangerously hot .
  2. Remove the Filler Cap
    Open the oil filler cap located on the transmission side of the engine. This allows air in to help oil drain out smoothly .
  3. Locate and Remove the Drain Plug
    Place your pan under the engine. Remove the drain plug using the correct socket (commonly 21mm, but confirm on your specific bike). Let all the old oil drain out completely .
  4. Inspect and Clean
    While the oil drains, inspect the drain plug for metal shavings. Clean the plug and the area around it with a rag.
  5. Reinstall the Drain Plug
    Once drained, reinstall the drain plug. For the 1979 RM80, tighten to 23 Nm (16.5 lb-ft) using a torque wrench .
  6. Refill with Fresh Oil
    Pour the specified amount of SAE 10W-40 motorcycle transmission oil into the filler port. For the 1979 RM80, the manual specifies 700ml (1.48 US pints) .
  7. Replace and Tighten the Filler Cap
    Secure the filler cap, tightening it to spec. Wipe down any spilled oil .
  8. Run the Engine and Check the Oil Level
    Run the engine for 1-2 minutes to circulate new oil. Turn off, wait a few minutes, then check oil level using the oil level check screw on the side of the case. Remove the screw; if oil comes out, the level is correct. If not, add a little more oil .
  9. Dispose of Old Oil Responsibly
    Pour used oil into a sealed container and take it to a recycling center or auto parts store.

Model-Specific Callouts for the 1979 Suzuki RM80

  • Oil Capacity: Some older manuals cite 700ml as the correct fill volume for a complete change . More recent recommendations for similar engines suggest 550ml for standard changes; always crosscheck if unsure .
  • Oil Type: Use 10W-40, JASO MA-rated oil designed for wet-clutch motorcycles. Automotive oils may cause clutch slippage .
  • Drain Plug Torque: Overtightening will strip case threads. Always use a torque wrench set to 23 Nm .
  • Level Inspection: This bike uses a side-level check screw, not a dipstick. Never overfill, as excess oil can cause gearbox drag or leaks .
  • No Oil Filter: The 1979 RM80 does not use a separate oil filter cartridge. Oil changes alone maintain system cleanliness.

Tips and Reminders

  • Check for oil leaks around the drain and filler after your first ride.
  • Worn gaskets or O-rings around plugs may require replacement to prevent leaks.
  • Regularly scheduled oil changes (every 10-20 hours of riding or after muddy races) help vintage engines last longer.

Following these steps ensures your 1979 Suzuki RM80 transmission runs smoothly and reliably, keeping you tearing up the track or trail season after season.

Related Shopping Categories

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Shop Oil Fillers and Drain Plugs for a 1979 Suzuki RM80 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.