How to Change the Oil in a 1983 Yamaha IT250

Shop parts for a 1983 Yamaha IT250 Dirt Bike.

Changing the oil in your 1983 Yamaha IT250 is a key part of regular maintenance, ensuring the engine and transmission deliver top performance and longevity. While the IT250 uses a 2-stroke engine—meaning there's no engine oil in the crankcase as with 4-strokes—it does require regular transmission oil changes. Here's how to perform this service, with specific details, necessary tools, and model-specific tips for the IT250.

Tools and Supplies Needed

  • Sockets and ratchet (typically 17mm or 19mm for drain bolt)
  • Torque wrench (for proper tightening)
  • Drain pan
  • Measuring cup or oil jug
  • Funnel
  • Rags or shop towels
  • Replacement oil (see manual for specifications; most use 10W-30 or 10W-40 non-friction-modified motor oil for transmission)
  • Gloves

Preparation Steps

  • Warm up the engine for 2-3 minutes. This ensures the oil drains thoroughly by reducing viscosity.
  • Turn off the engine and secure the bike on a stable stand with the bike level.

Step-by-Step Oil Change

  1. Locate the Drain Bolt
    On the 1983 Yamaha IT250, the transmission oil drain bolt is located on the bottom of the engine case. Consult your service manual or inspect the underside if you're unsure. Place the oil drain pan beneath this bolt.
  2. Remove the Drain Bolt
    Using the socket and ratchet, carefully loosen and remove the drain bolt. Let all oil completely drain into the pan. Inspect the oil for shavings or debris.
  3. Inspect Washer and Clean the Bolt
    Check the drain bolt washer (crush washer) for wear or flattening. Replace it if necessary to prevent oil leaks. Wipe the bolt clean.
  4. Reinstall the Drain Bolt
    Once the oil has stopped dripping, reinstall the drain bolt by hand to avoid cross-threading. Tighten with a torque wrench to manufacturer specification. For similar Yamaha models, typical torque values are around 23 ft-lb (3.2 m-kg), but always verify with your specific service manual to avoid damage.
  5. Add Transmission Oil
    Locate and remove the transmission oil fill cap (usually on the right side of the engine above the clutch cover). Using a funnel and measuring cup, add the correct amount and type of oil. For many Yamaha 2-strokes of this era, the capacity is around 750 ml (0.8 US qt), but refer to the IT250 manual for exact specifications.
  6. Replace the Fill Cap
    Ensure the fill cap is tightened securely.
  7. Check for Leaks
    Start the bike and let it idle briefly. Shut it off and check around the drain bolt and gasket for oil leaks. Tighten as needed.
  8. Proper Disposal
    Pour the old oil into a sealable container and take it to a recycling facility. Do not pour used oil down drains or on the ground.

Model-Specific Call-Outs for 1983 Yamaha IT250

  • This bike is a 2-stroke with a separate transmission oil reservoir—do not confuse engine premix oil (mixed in your gas tank) with transmission oil changes.
  • Always check the oil level sight glass or dipstick after filling to verify the correct level. Over- or under-filling can cause clutch or gearbox issues.
  • A common issue with older bikes like the IT250 is rounded drain bolt heads. Replace the bolt if worn to avoid stripping and future headache.
  • If you have aftermarket parts like a billet clutch cover, verify it does not alter oil capacity requirements.
  • The proper specification of oil has changed little: Use a motorcycle-specific gear oil with the correct viscosity as listed in the IT250 service manual.

Maintenance Tips for IT250 Owners

  • Change transmission oil every 10-15 hours of riding, or sooner after races, heavy mud use, or break-in periods.
  • Inspect clutch cover gasket for leaks during each change.
  • Check for excessive metal shavings in oil—this is an early sign of clutch, bearing, or transmission issues.
  • Keep a log of each oil change with hours ridden for easier maintenance scheduling.

Conclusion

Changing the transmission oil on your 1983 Yamaha IT250 is a simple yet critical task to ensure lasting performance. With basic hand tools, correct oil, and the steps above, you keep your iconic two-stroke running strong for years—and your next ride trouble-free.

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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.