How to Change the Oil in a 1977 Yamaha IT250

Shop parts for a 1977 Yamaha IT250 Dirt Bike.

Routine oil changes are essential to keep your 1977 Yamaha IT250 performing at its best. Although this two-stroke dirt bike does not use engine oil in the same way as a four-stroke, it still requires regular transmission oil changes to ensure smooth shifting and to protect internal components. Below is a step-by-step guide specific to the IT250, including the tools you need, the recommended fluids, and special tips just for this classic Yamaha model.

Tools and Supplies Needed

  • Socket wrench set (for removing drain and fill bolts)
  • Drain pan
  • Shop rags or paper towels
  • Funnel
  • Replacement crush washer (optional but recommended)
  • New transmission oil (Yamaha and many riders recommend SAE 10W-30 or 10W-40 non-friction-modified oil; reference the owner's manual for specific grade and volume. Most sources suggest about 1000cc, or roughly 1 liter)
  • Ratchet straps (for keeping the bike upright, especially in smaller workspaces)
  • Gloves (to protect your hands)

Preparation Steps

  • Warm up the bike for a few minutes to thin the oil, allowing for more complete drainage. Turn off the engine before proceeding.
  • If you have a small workspace, use a ratchet strap to hold your bike upright and steady, or ask someone to help keep it vertical while you work. Draining oil with the bike upright helps remove as much old oil as possible.
  • Place the drain pan under the engine's oil drain bolt.

Step-by-Step Oil Change Process

  1. Locate the Drain Plug
    The drain plug is typically on the lower left side of the engine case, underneath the motor. Consult your service manual if you have trouble identifying it.
  2. Remove the Drain Plug
    Use your socket wrench to remove the drain bolt. Allow the oil to drain completely into the pan. For a more thorough flush, you can pour a small amount of fresh oil into the fill port once the draining slows, until the fluid running out is clean. This helps remove residual contaminants from the gearbox.
    Tip for the IT250: The design allows oil from the clutch and transmission to drain together, so let it sit for an extended period–overnight if possible–for the most thorough job. While this isn't always necessary, it will help get every last drop out, especially in older or rarely serviced bikes.
    Optional: Replace the crush washer on the drain plug to prevent future seepage.
  3. Reinstall the Drain Plug
    Once draining is complete and the oil drip has stopped, wipe the area clean. Reinstall the drain plug snugly but do not overtighten; refer to the service manual for torque specs if you have a torque wrench. Overtightening can damage threads, which is a common issue on older aluminum cases.
  4. Fill with New Oil
    Find the transmission oil fill cap, usually located on the top or side of the clutch cover. Remove it and use a funnel to add new oil.
    For the 1977 IT250, the recommended fill amount is 1000cc (1 liter) of SAE 10W-30 or 10W-40. You can double-check the exact specification in your owner's manual or service manual if available.
  5. Check the Oil Level
    Some models have a dipstick or sight glass (refer to your bike's service manual). If you have a dipstick, insert it without threading it in to check the level–do not screw it down, as this can give a false reading. The oil should be between the minimum and maximum marks. If using a sight glass, the bike must be upright to get an accurate reading.
    For best results, let the bike sit upright overnight after filling. The oil will have time to settle between the clutch and gearbox sides, ensuring an accurate reading.
  6. Reinstall the Fill Cap
    Clean the area around the cap and tighten it securely by hand.
  7. Start the Engine and Inspect
    Run the engine for a few minutes, shift through all gears, then shut it off and check for leaks at the drain and fill plugs. Once the engine cools, recheck oil level and top off as needed.

1977 Yamaha IT250-Specific Call-Outs

  • The IT250—s drain bolt design usually allows both the clutch and transmission case oil to drain simultaneously, but restricted passages or residual oil from previous overfilling can slow draining. If you suspect sludging, allow plenty of time for complete drainage.
  • Since there is no oil filter on a two-stroke like the IT250, routine changes are especially important for protecting bearings and gearbox components.
  • The oil check procedure recommends filling, letting the bike stand upright overnight, and checking the level again before riding. This ensures any residual oil has migrated to the sump and provides a true reading.
  • Always use an oil that is compatible with wet clutches to prevent clutch slippage. Avoid automotive oils with friction modifiers unless Yamaha explicitly approves them.

Disposal and Final Steps

  • Dispose of used oil responsibly at your local recycling center or auto parts store.
  • Make a note of the date and mileage/hours for your maintenance records.

By following these steps, you'll maximize the life and performance of your vintage Yamaha IT250—keeping your ride running strong for years to come. Enjoy the trails.

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Shop Oil Fillers and Drain Plugs for a 1977 Yamaha IT250 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.