How to Change the Oil in a 1987 Honda Z50: A MotoSport.com Exclusive Guide

Shop parts for a 1987 Honda Z50 Dirt Bike.

Regular oil changes are essential for keeping your 1987 Honda Z50 running smoothly and ensuring maximum engine life. While the process may seem daunting to new owners, it is a straightforward DIY task when you know the steps. Below, you’ll find a complete, proprietary MotoSport.com guide with the specific tools needed, step-by-step instructions, and important model-specific tips for your 1987 Honda Z50.

Tools and Supplies Needed

  • 17mm socket and ratchet or wrench (for the oil drain bolt)
  • Pliers (for stubborn bolts, optional)
  • Oil catch pan or suitable drain container
  • Honda recommended 10W-40 four-stroke engine oil (or equivalent)
  • Measuring container (to verify correct oil amount – 600 ml / 0.6 US quarts)
  • Funnel (optional, for mess-free filling)
  • New sealing washer for the drain bolt (recommended for every oil change)
  • Clean shop rags or paper towels
  • Nitrile or mechanic gloves (to keep your hands clean)

Step-by-Step Instructions

  1. Warm Up the Engine (Optional)
    Briefly run your Z50 for 3–5 minutes to thin the oil, which aids draining. Then turn the engine off and allow it to sit for 2–3 minutes to let the oil settle.
    Tip: If your engine is cold and you prefer not to run it, you can still proceed—just be aware colder oil drains more slowly.
    Model Note: The 1987 Z50 engine is nearly identical to other Z50 and early Honda horizontal engines, so procedures closely match later and earlier models.
  2. Stabilize the Motorcycle
    Set your Z50 on a level, secure surface. Use the kickstand or a work stand. Ensure the bike is upright for proper oil drainage.
  3. Locate and Remove the Oil Fill Cap/Dipstick
    Unscrew and remove the oil fill cap (or cap/dipstick) from the right side of the engine. This lets air in and speeds up the draining process.
  4. Remove the Oil Drain Bolt
    Place your oil catch pan directly under the crankcase. Using the 17mm socket or wrench, carefully loosen and remove the oil drain bolt underneath the engine. Pull the bolt (with washer) out and set aside. Allow the oil to drain completely.
    Model Callout: The 1987 Z50, like most Z50s, features a 17mm drain bolt. Do not accidentally remove the cam chain tensioner push rod bolt—it is located nearby and can cause additional problems if removed.
  5. Help the Last Oil Out
    Gently tilt the Z50 from side to side to ensure all remaining oil drains from the crankcase.
  6. Replace the Sealing Washer
    Remove the old sealing washer from the drain bolt and fit a new one. This helps prevent leaks.
  7. Install the Drain Bolt
    Screw the drain bolt back in by hand, then tighten using your wrench or socket to 18 lb-ft (24 Nm, 2.5 kgf-m)—don’t over-tighten, as the engine case threads are delicate on these small bikes.
  8. Refill with the Correct Oil
    Measure out 600 ml (0.6 US quarts) of engine oil. Using a funnel, pour the oil into the crankcase.
    Tip: Some manuals and forums reference 0.7 or 0.8 liters for a full disassembly, but for a routine drain-and-fill, 0.6 liters is correct and safe for your 1987 Z50.
  9. Reinstall the Oil Fill Cap/Dipstick
    Install the cap tightly and wipe away any excess oil.
  10. Engine Check and Oil Top-Off
    Start the engine and let it idle for 3-5 minutes. Be sure to check for leaks around the drain bolt. Shut off the engine and let the oil settle for 2-3 minutes.
    With the bike held upright, remove the dipstick and check the oil level. Top up if needed, but do not overfill.
  11. Dispose of Used Oil Properly
    Take your used oil to a recycling center—never dump it outdoors.

Model-Specific Tips and Cautions for the 1987 Honda Z50

  • Drain Bolt Location: Easily accessible underneath the engine; make sure you do not confuse it with the cam chain tensioner bolt, which is also visible from underneath and should not be removed.
  • Oil Capacity: 0.6 liters (600 ml) is correct for a standard oil change on your 1987 Z50; using more may risk overfilling and causing leaks or poor performance.
  • Sealing Washer: These crush washers can become flattened or deformed after use. Always replace when changing the oil to avoid leaks.
  • Thread Sensitivity: The engine cases on these small Hondas are soft aluminum. Do not overtighten the drain bolt; use a torque wrench when possible to avoid stripping threads.

Final Thoughts

A routine oil change is an easy way to keep your 1987 Honda Z50 running for years. For more OEM parts, oil, and guides, MotoSport.com offers everything owners need for simple and advanced DIY maintenance.

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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.