How to Change the Oil in a 1988 Yamaha XT350

Shop parts for a 1988 Yamaha XT350 Dirt Bike.

Keeping your Yamaha XT350's engine running smoothly depends on regular oil changes. This how-to guide, proprietary to MotoSport.com, covers every tool, step, and special consideration when changing the oil on a 1988 Yamaha XT350. Let's dive in.

Tools and Supplies Needed

  • Socket set (most bolts will require a 12mm and 10mm socket)
  • Torque wrench (for reinstalling bolts at the correct spec)
  • Drain pan (to catch used oil)
  • Funnel
  • Clean shop rags
  • Rubber gloves
  • New oil filter (Yamaha Genuine recommended or quality aftermarket part)
  • Replacement oil: SAE 10W-40 or SAE 20W-40, API SE/SF or higher classification
  • New drain plug washer (aluminum sealing ring: 12x1mm recommended)
  • Flathead screwdriver or Phillips (for filter cover if necessary)
  • Service manual (optional but highly recommended)

Preparation

  • Warm up the engine for 2–3 minutes to help the oil flow more easily; do not overheat.
  • Turn off the engine and place the bike upright on a safe, level surface.
  • Remove the skid plate (if installed) for easier access.

Step-by-Step Oil Change

  1. Remove the Oil Drain Plug
    • Place the drain pan under the engine.
    • Use a 12mm socket to loosen and remove the drain plug located at the bottom of the crankcase.
    • Allow oil to fully drain (expect about 1.3L–1.4L to come out if you’re also replacing the filter).
  2. Remove and Replace the Oil Filter
    • Use a socket or screwdriver to remove the oil filter cover bolts (usually 10mm).
    • Take out the old filter and O-ring. Carefully wipe the filter housing with a clean rag.
    • Insert the new filter, checking orientation (usually “out” faces the cover).
    • Install a new O-ring if provided.
    • Reinstall the cover and torque bolts to the manufacturer’s specification (typically 10Nm, but verify in manual).
  3. Reinstall Drain Plug and Washer
    • Install a new crush washer (12 x 1 mm recommended) on the drain plug.
    • Reinstall by hand, then torque to spec (check service manual; usually around 34Nm).
  4. Fill with Fresh Engine Oil
    • Remove the oil filler cap.
    • Add SAE 10W-40 or SAE 20W-40 oil. Total capacity: 1.6L, oil/filter change: 1.4L.
    • Pour slowly, stopping periodically to check the level with the dipstick (do not overfill).
  5. Prime the Oil System (Critical on the XT350.)
    • The XT350 has a bleed bolt on top specifically to prime the oil pump after an oil/filter change.
    • Crack the bleed bolt until oil seeps out, indicating the chamber and pump are primed. Tighten the bleed bolt (torque: 5Nm).
    • This step helps avoid a dry start, as there is no oil pressure light on this model.
  6. Start the Engine and Check for Leaks
    • Briefly start the engine (10–20 seconds) and check for leaks at the drain plug and filter cover.
    • Stop the engine, allow oil to settle for a few minutes.
    • Check oil level and top up if needed.
  7. Final Checks
    • Ensure filler cap is tight and everything is leak-free.
    • Safely dispose of used oil and filter according to local regulations.
    • Record the service and next change interval.

Important 1988 XT350-Specific Tips

  • Priming the oil pump via the bleed bolt after an oil change is essential to prevent engine damage due to lack of oil pressure on startup.
  • No oil light: The XT350 lacks a warning light, so proper priming and checking is your only assurance of oil flow.
  • Use a new sealing washer on the drain plug every time to avoid leaks.
  • Never add chemical additives to the oil—these can damage the wet clutch system.
  • Recommended oil level: Re-check with dipstick after the engine is run and oil is allowed to settle. Do not overfill.
  • Oil type: Yamaha recommends API SE/SF or higher, SAE 10W-40 or 20W-40 type SE oil.

Recommended Oil and Filter

  • Oil: SAE 10W-40 or 20W-40 motor oil, API SE/SF or newer (Yamalube preferred).
  • Oil Filter: Genuine Yamaha or high-quality aftermarket equivalent.
  • Quantity: 1.4L with filter change, 1.3L without.

Conclusion

Changing the oil on your 1988 Yamaha XT350 is easy with the right tools and knowledge. Following this guide will help ensure the longevity and performance of your vintage dual-sport. For all your Yamaha XT350 parts and fluids, trust MotoSport.com for the best selection and service.

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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.