How to Change the Oil in a 2018 Honda CRF150R

Shop parts for a 2018 Honda CRF150R Dirt Bike.

This proprietary MotoSport.com guide will walk you step-by-step through changing the oil on your 2018 Honda CRF150R, highlighting model-specific tips, best practices, and all tools required for a safe, effective service.

Tools and Materials Needed

  • 10mm socket and ratchet or box wrench (for drain bolts)
  • Oil catch pan
  • Funnel
  • Clean rags or shop towels
  • Replacement engine oil (Honda GN4 10W-40 is recommended)
  • Oil filter (OEM or compatible, such as HI-FLOW HF116)
  • Replacement crush washers for drain bolts
  • Torque wrench
  • Flat-head screwdriver (for removing small panels, if necessary)
  • Gloves (recommended)

Model-Specific Callouts

  • The 2018 CRF150R has separate engine and transmission oil compartments. Change both for best results.
  • Recommended oil volumes:
    • Engine side: 590cc (20 oz) if changing the filter, 560cc (18.9 oz) if not changing the filter
    • Transmission side: 580cc (19.6 oz)
  • Change engine oil every 6 hours of riding or after every 6 races, and the oil filter every 12 hours (every other oil change). Transmission oil should also be replaced every 12 hours or as needed for extreme conditions

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  • Always use a new crush washer on each drain bolt to prevent leaks

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  • Do not overtighten the drain bolts – stripping them is a common and costly mistake

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Step-by-Step Oil Change Instructions

  1. Warm Up the Engine
    Start the bike and let it idle for 2–3 minutes. This warms the oil, ensuring it flows out easily and brings contaminants with it.
  2. Turn Off Engine & Secure Bike
    Use a stand to keep your CRF150R level and stable. Let the bike cool for a minute, so you don't burn yourself.
  3. Drain the Engine Oil
    • Locate the engine oil drain bolt beneath the right side of the engine.
    • Position your pan under the bolt, use a 10mm socket/wrench to loosen and remove it.
    • Allow all oil to drain completely. Carefully remove the oil filler cap/dipstick on the right side to speed this up.
    • Discard the old crush washer.
  4. Change the Oil Filter
    (Recommended every other oil change)
    • Use the 10mm wrench to remove the oil filter cover (just above the drain bolt).
    • Note orientation and remove the old oil filter—pay attention to the spring behind it.
    • Wipe the cover and cavity clean. Insert the new filter, spring side facing in.
    • Reinstall the cover, tightening bolts evenly and to manufacturer-recommended torque.
  5. Reinstall the Drain Bolt
    • Fit a new crush washer to the bolt.
    • Thread the drain bolt back by hand, then torque to spec (be gentle–over-tightening can strip these bolts).
  6. Add Fresh Oil
    • Using a funnel, fill the crankcase with Honda GN4 10W-40 oil:
      • With filter change: 590cc (20 oz)
      • Without filter change: 560cc (18.9 oz)
    • Pour slowly to avoid overflow. Do not overfill.
    • Reinstall the dipstick and tighten it snugly.
  7. Drain & Refill Transmission Oil (Recommended every 12 hours)
    • Locate the separate transmission drain bolt on the left case. Remove bolt, drain oil fully, replace the washer.
    • Reinstall the bolt and torque to spec.
    • Add 580cc (19.6 oz) of the same oil (Honda GN4 10W-40) via the clutch-side filler cap.
  8. Final Checks
    • Start the engine and let it idle for 1–2 minutes. Shut off.
    • After a couple minutes, check oil level with the dipstick. Add oil if needed to reach the upper mark.
    • Check for leaks at all bolts and covers.
    • Dispose of old oil and filter responsibly at a recycling center.
  9. Test Ride and Monitor
    • Take a short test ride. Recheck for leaks and oil level once the bike cools.

Pro Tips for the 2018 Honda CRF150R

  • Keep a maintenance log noting dates and hours run for every oil change (especially important for high-revving mini race bikes like the CRF150R).
  • Always use high-quality replacement filters—OEM or well-reviewed aftermarket brands like HI-FLOW (HF116) are popular for their reliability and cost savings

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  • Inspect the drained oil for metal flakes or grit—this can help detect any abnormal engine wear early.
  • Never use old or re-used crush washers; oil leaks often occur due to washer failure.

Proper oil changes on your 2018 Honda CRF150R are essential for performance and reliability. With regular care, this high-performance mini will keep running strong whether you’re at the track or carving up the trails.

Related Shopping Categories

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Shop Oil Filler and Drain Plugs for a 2018 Honda CRF150R 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.