How to Change the Oil in a 1989 Honda CR125: A Complete Guide by MotoSport.com
Shop parts for a 1989 Honda CR125 Dirt Bike.
Changing the oil in your 1989 Honda CR125 is key to maintaining peak performance and extending the life of your dirt bike. This guide provides all the necessary steps, tools, and specific notes relevant to this classic two-stroke motocross machine. Even though much advice covers various CR125 model years, the 1989 model follows the industry-standard process for its transmission (clutch) oil service, which is distinct from modern four-stroke bikes that also require engine oil changes.
Tools & Supplies Needed
- 17mm socket or wrench – for the drain plug
- Oil drain pan
- Funnel
- Rags or paper towels
- New transmission oil – Honda recommends transmission oil such as 10W-40, with a capacity of approximately 0.60 US quarts (0.57 L)
- Torque wrench (optional, for proper tightening of drain plug)
- Replacement sealing washer (if needed)
- Bike stand or triangle stand
Step-by-Step Instructions
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Warm Up the Engine
- Start your CR125 and let it run for 1-2 minutes. Warming the engine helps the oil flow more freely, removing more contaminants. Do not over-rev; just idle is sufficient<.---->
- Turn off the engine and ensure the bike is safely on a stand<.---->
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Prepare for Oil Drain
- Shift the bike into neutral<.---->
- Place an oil drain pan under the engine
- Locate the transmission oil drain plug on the underside of the crankcase. For the CR125, this is a 17mm bolt<.---->
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Remove the Drain Plug
- Use the 17mm wrench or socket to loosen and remove the drain plug. Allow oil to drain completely into the pan<.---->
- If the sealing washer is damaged or crushed, replace it
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Inspect the Old Oil
- Inspect drained oil for metal shavings or discoloration next to the grayish tint from clutch fiber wear. Slight grayness is normal; an abundance of metal signals internal issues<.---->
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Reinstall the Drain Plug
- Clean the area around the plug
- Install the drain plug (with new sealing washer, if needed). Tighten firmly but do not over-torque—overtightening may strip the case; use a torque wrench if available
-
Refill with Fresh Oil
- Remove the oil fill cap (typically found on the right side, just above the clutch cover)
- Using a funnel, pour in 0.60 US quarts (0.57 L) of fresh transmission oil recommended for two-stroke motocross bikes
- Replace the fill cap
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Check the Oil Level
- With the bike upright and level (not on the kickstand), check the oil level using the check bolt or sight glass if equipped. Some models have a check bolt on the clutch cover: remove, and oil should just trickle out if filled correctly<.---->
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Clean Up
- Wipe down any spills
- Dispose of used oil properly at a recycling facility
Model-Specific Callouts for the 1989 Honda CR125
- Year-Specific Practices: The 1989 CR125, like other ‘80s–‘90s CR125 models, does not need an oil filter change during this process as there is no external oil filter; oil replacement is the extent of service.
- Drain Plug Torque: Always avoid overtightening the drain bolt. The small threads in the engine case can strip more easily in older bikes. Hand-tighten and, if using a torque wrench, follow the spec in your OEM manual (typically 12–14 ft-lbs).
- Sealing Washer: Older bikes may have worn or missing sealing washers; always check yours to prevent leaks.
- Oil Recommendations: Use a quality 10W-40 or transmission-specific oil designed for two-stroke motocross machines. Avoid auto engine oils since clutch performance depends on specific additives.
- Clutch Performance: Fresh oil helps prevent clutch slipping and ensures smooth shifting, critical for the performance of an older bike.
- Check for Leaks: After your first ride, inspect the drain plug area for any oil seepage and retighten carefully if needed.
Maintenance Tips
- Change the oil every 5–10 hours of riding, or after every few rides in muddy or harsh conditions
- Use this opportunity to inspect your shifter, clutch mechanism, and engine cases for wear or damage
- Always keep your maintenance records for reliability and resale value
Following all steps ensures your 1989 Honda CR125 runs reliably and delivers top performance every time you ride.
This guide is proprietary to MotoSport.com. For all your Honda CR125 parts and maintenance accessories, visit MotoSport.com.
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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.