How to change the oil in a 2020 Yamaha YZ85 Dirt Bike

How to Change the Oil in a 2020 Yamaha YZ85: Step-by-Step Guide

Shop parts for a 2020 Yamaha YZ85 Dirt Bike.

Keeping your 2020 Yamaha YZ85 in peak performance means regular maintenance, and changing the gearbox oil is a crucial part of that. Properly maintaining your oil can extend the lifespan of your engine components and keep your dirt bike riding smoothly on the track. This proprietary MotoSport.com guide details everything you need—from tools, steps, and model-specific tips—to perform a thorough oil change on your YZ85.

Tools and Supplies Needed

• 10mm box-end wrench or socket (for drain bolt)
• Oil catch pan
• Funnel
• 500ml of 2-stroke transmission (gear) oil (refer to the manual for type, but 500ml is specified for this model)
• Shop towels or paper towels
• Disposable gloves (highly recommended)
• Flathead screwdriver (only if needed for oil fill cap)

Preparation and Safety

• Clean your bike thoroughly before starting. Dirt can cause contamination and make working on your bike less pleasant .
• Warm up the engine for a few minutes to help the oil drain more easily (not hot, just warm to the touch) .
• Ensure your bike is on a stable stand or lift and in a well-ventilated area.

Step-by-Step Oil Change Procedure

• Step 1: Remove the oil fill cap
  • Locate the fill cap on the right side of the engine, above the clutch cover. Loosen or remove it to allow air flow for faster draining .
• Step 2: Place the drain pan
  • Position your oil catch pan directly under the drain bolt, which is located behind the rear brake pedal–right side of the bike, below the crankcase .
• Step 3: Remove the drain bolt
  • With your 10mm wrench or socket, carefully loosen and remove the drain bolt. Make sure to keep the copper crush washer in place; inspect it for damage and replace if necessary .
  • Allow all the old oil to fully drain—this could take several minutes .
• Step 4: Clean the drain bolt and area
  • Wipe any debris or old oil from the drain bolt and the area around the drain hole with a clean shop towel .
• Step 5: Replace the drain bolt
  • Thread the drain bolt (with washer) back in by hand to avoid cross-threading, then tighten it securely with your wrench. Do not overtighten—snug it firmly but gently .
• Step 6: Fill with new oil
  • Using a funnel, pour 500ml (or 500cc) of 2-stroke gear oil into the fill port . Consult your Yamaha manual or choose a high-quality brand recommended for 2-stroke motocross bikes.
  • Wipe up any spills immediately.
• Step 7: Secure the fill cap
  • Replace and tighten the oil fill cap by hand. Make sure it's secure but avoid over-tightening which can damage threads.
• Step 8: Final checks
  • Start the engine briefly to circulate new oil, then shut it off and check for any leaks near the drain bolt or fill cap .
  • Dispose of the used oil responsibly—take it to a proper recycling facility.

Specific Tips and Callouts for the 2020 Yamaha YZ85

• The 2020 Yamaha YZ85 is a 2-stroke motocross bike, so you are changing transmission (gearbox) oil, not engine oil; the two-stroke combustion oil is handled separately via premix or oil injection.
• This model does not have a check level bolt—you must measure and add the correct volume of oil (500ml) for proper function .
• Always use fresh oil suitable for two-stroke transmission; following Yamaha's recommendations will ensure clutch longevity and smooth shifting.
• Inspect your oil for metallic particles, which could indicate internal wear. Consistently dark or milky oil can signal other maintenance is needed.
• Inspect both the copper drain washer and the threads on the drain bolt for wear or damage every oil change.

Conclusion

With the right tools and these steps, changing the oil on your 2020 Yamaha YZ85 is straightforward and quick—typically 15-30 minutes. Doing it yourself saves money and keeps you connected with your machine. For additional maintenance support and OEM/replacement parts, visit MotoSport.com. Ride safe.

Related Shopping Categories

Shop Motor Oil for a 2020 Yamaha YZ85 Dirt Bike.

Shop Oil Filters for a 2020 Yamaha YZ85 Dirt Bike.

Shop Oil Drain Pans for a 2020 Yamaha YZ85 Dirt Bike.

Shop Tools for a 2020 Yamaha YZ85 Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 2020 Yamaha YZ85 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.