How to Change the Oil in a 1979 Honda XR250R: MotoSport.com Guide

Shop parts for a 1979 Honda XR250R Dirt Bike.

If you own a 1979 Honda XR250R, regular oil changes are crucial for engine longevity & peak performance. The XR250R uses a dry-sump lubrication system with the oil reservoir in the frame, which makes the oil change process unique compared to more conventional setups. Here’s a step-by-step proprietary guide to help you change the oil confidently and keep your classic dirt bike running strong.

Tools and Supplies Needed

  • Ratchet and sockets (mainly 8mm, 10mm, and 12mm)
  • Drain pan to catch old oil
  • New oil (consult your manual, but quality 10W-40 or 20W-50 motorcycle oil is recommended; typically 1.4 – 1.8 quarts / 1.3 – 1.7 liters)
  • New oil filter (check compatibility for the ‘79 XR250R; HF112 is commonly listed for XR250 models after the original year, verify fitment)
  • Funnel and/or clear tubing for filling without spillage
  • Gloves and shop towels
  • Graduated beaker or measuring cup (for accurate oil volume)

Preparation

  • Make sure the bike is on a stable, level surface.
  • Start the engine and let it run for a few minutes. This warms the oil, allowing it to drain more thoroughly.
  • Shut off the engine and secure the bike upright, using a stand if available.

Step-by-Step Oil Change Procedure

  1. Remove the Oil Fill Cap/Dipstick
    Loosen and remove the oil fill cap/dipstick (located between the gas tank and the handlebars). This will vent the system and improve drainage.
  2. Drain the Oil
    • Place a drain pan beneath the drain bolt on the underside of the frame (near the skid plate).
    • Use the appropriate socket to carefully loosen and remove the frame’s drain bolt. Allow the oil to drain completely.
    • Some models feature a secondary drain bolt on the engine case – remove this as well to drain residual oil from the crankcase.
    • Watch for crush washers on both bolts; inspect and replace if damaged.
  3. Replace the Oil Filter
    • Locate and remove the oil filter cover bolts. Generally, three bolts secure the cover.
    • Take note of the orientation of the old filter and any spring or O-ring present.
    • Install the new oil filter, ensuring all seals are properly seated.
    • Reinstall the cover and tighten the bolts evenly.
  4. Reinstall Drain Bolts
    • Once the oil has finished draining, clean the threads and reinstall both drain bolts with proper torque. Don’t overtighten.
  5. Add New Oil
    • Using a funnel or clear tubing, pour about 1.4 liters (approximately 1.5 US quarts) of your preferred motorcycle oil into the fill port.
    • The XR250R uses a dry-sump system; oil circulates through the frame before reaching the engine. Air pockets are common, so do not overfill initially.
  6. Prime the System and Measure Level
    • Start the engine and let it run for 30–60 seconds. Shut off and wait a minute for the oil to settle.
    • Check the oil level with the dipstick. On the XR250R, always check with the dipstick resting on the threads (not screwed in).
    • Add oil in small increments as needed, repeating the process until the oil level stabilizes near the upper mark.
  7. Final Double-Check
    • After a short ride, recheck oil level. Top off only if necessary.
    • Inspect for leaks at both drain bolts and filter cover.

Model-Specific Tips and Call-Outs for the 1979 XR250R

  • The oil fill location is tight–take care not to spill. Using a funnel with a spout or tubing helps prevent messes.
  • Older XR250Rs (including 1979) often lack an external oil cooler found in later models–pay close attention to oil intervals, especially after hard riding.
  • The dry-sump frame design means it’s normal for some air to cause false readings until oil circulates. Always check the level after running the engine and letting oil settle.
  • If the oil filter cover gasket appears worn or brittle, replace it to prevent leaks.
  • Expect drain plug washers to deform with age—replacing them is good practice every oil change.

Proprietary MotoSport.com Oil Change Recommendations

  • Stick to a high-quality motorcycle oil within the recommended viscosity range—most owners use non-synthetic or semi-synthetic 10W-40 for vintage Honda thumpers.
  • Change oil every 10–15 riding hours, or after any heavy mud riding, to maximize engine life.
  • Maintain a log of oil and filter changes with date and hours ridden.

Conclusion

Changing the oil on the 1979 Honda XR250R isn’t difficult, but attention to detail keeps this legendary dirt bike running for decades. For all your parts, tools, and expert gear, MotoSport.com has you covered—gear up and ride on.

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Shop Oil Fillers and Drain Plugs for a 1979 Honda XR250R 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.