How to Change the Oil in a 1999 Kawasaki KX250: A Complete Guide
Shop parts for a 1999 Kawasaki KX250 Dirt Bike.
Changing the transmission oil in your 1999 Kawasaki KX250 is crucial for maintaining optimum performance and ensuring the longevity of internal components. This guide—exclusive to MotoSport.com—covers every step, the tools you'll need, best practices, and unique tips for this specific dirt bike model.
Tools and Supplies Needed
- Socket wrench set (8mm and 12mm sockets)
- Drain pan
- Clean funnel
- Measuring cup (such as Ratio Rite)
- Shop towels or rags
- New crush washer for the drain bolt
- Flathead screwdriver (optional for cleaning around drain bolt area)
- Kawasaki-recommended gear oil (see details below)
- Rubber gloves (optional, for cleaner hands)
Recommended Oil for 1999 KX250
- Kawasaki recommends a high-quality, 2-stroke gear oil.
- Capacity: 750ml (approx. 0.80 quarts)
- Popular choices: SAE 80W gear oil or Maxima MTL 80W formulated for two-strokes.
- Do NOT use synthetic oils with friction modifiers, as these can cause clutch slippage in this model.
Some users report using non-synthetic Rotella T4, but confirm it contains no friction modifiers if you go this route.
Never use Rotella T6 synthetic in the KX250 transmission.
Steps to Change the Oil on a 1999 Kawasaki KX250
- Warm up the engine briefly (1-2 minutes) to thin the oil. Letting the oil warm up ensures more debris and old oil come out when you drain it. Shut the bike off and let it rest for a moment.
- Secure the bike upright on a stand. This allows all oil to drain completely–a critical step for thorough maintenance.
- Locate the transmission oil drain bolt. On the right side of the 1999 KX250, the drain bolt is at the bottom of the transmission case.
- Place a drain pan under the bolt and use the correct socket (typically 12mm, but check yours) to remove the bolt. Allow the oil to drain fully (let it drip for several minutes).
- Inspect the drain bolt and washer. The drain bolt usually has a copper or aluminum crush washer that should be replaced every change to prevent leaks. If missing or worn, replace before reinstalling.
- Clean the drain bolt with a rag. Wipe away any metal shavings or sludge from the magnet, if equipped.
- Reinstall the drain bolt and new washer. Hand-tighten, then snug up with a wrench. Do not overtighten–you're threading into aluminum. (Torque spec: about 13 ft-lbs/18 Nm)
- Remove the fill cap (located near the clutch cover on the right side).
- Use a measuring cup (Ratio Rite or similar) to pour in 750ml of fresh gear oil. Using the proper amount is especially important for this model–overfilling can cause fluid loss from the vent, and underfilling risks transmission damage.
- Reinstall the fill cap, ensuring it is clean and threads smoothly.
- Start the engine briefly (1-2 minutes) to circulate the oil. Shut the engine off and allow the bike to sit for a couple of minutes.
- Check oil level via the sight glass (if equipped) or by referencing your manual. Oil should be level with the mid to upper portion of the sight glass. If you used 750ml, you should be at the correct level for this model.
- Wipe away any spills, clean your tools and dispose of the old oil responsibly.
1999 KX250-Specific Call-Outs
- Replace the crush washer every oil change. Many KX250 owners forget this essential step, leading to oil leaks around the drain plug. If you lost the original, most hardware and auto parts stores offer suitable replacements in multipacks.
- This model's wet clutch is sensitive to oil types. Do not use any oil with friction modifiers or automotive engine oil–use only oils approved for wet clutches to prevent clutch slippage.
- Be gentle with the drain bolt. The 1999 KX250 crankcase is aluminum–overtightening can crack the case, causing costly repairs.
- Old, dirty oil can cause premature clutch wear and gear shifting problems. Regular 15-20 hour intervals are typical for transmission oil changes, but if you ride aggressively or in muddy conditions, consider changing even more frequently.
Wrap-Up
- Keep a maintenance log noting the date, type/brand of oil used, and hours ridden since the last oil change.
- If you notice persistent leaks, double-check your drain bolt torque and washer.
- Check the manual for any updates or specific procedures–your KX250 will thank you for it.
Maintaining your 1999 Kawasaki KX250 with regular oil changes ensures that you're always ready to enjoy the ride–on the trail or at the track. For all your genuine parts and expert dirt bike advice, MotoSport.com has you covered.
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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.