How to Change the Oil in a 1981 Yamaha IT250 – MotoSport.com Exclusive Guide

Shop parts for a 1981 Yamaha IT250 Dirt Bike.

Changing the transmission oil in your 1981 Yamaha IT250 is a crucial piece of regular maintenance that keeps your dirt bike running smooth and helps prevent major engine wear. This guide will walk you through the procedure, highlighting any model-specific tips and making sure you have all the tools and knowledge needed to get the job done right.

Tools & Supplies You’ll Need

  • Socket wrench set (including appropriate metric sockets, typically 19mm for drain plugs)
  • Drain pan to catch old oil
  • Clean rags or shop towels
  • New oil (SAE 10W/30 “SE” name-brand motor oil is recommended for the IT250)
  • Replacement oil filter or clean reusable filter (if equipped—some two-stroke models have a screen rather than a cartridge filter)
  • Funnel for pouring new oil
  • Gasket or O-ring for drain plug (optional, but replacing if worn is smart)
  • Gloves (optional but recommended)

Preparation Steps

  • Warm up your bike with a short ride so the oil flows out easier. If starting cold, be aware the oil may drain more slowly.
  • Position the bike upright on a level surface, using a center stand or support it safely.
  • Place your drain pan directly beneath the transmission drain plug.

Step-By-Step Oil Change Procedure

  • Remove the Transmission Filler Plug
    • Locate the oil/transmission filler plug, usually above the kick starter on the IT250.
    • Removing the filler plug helps the oil drain by allowing airflow.
  • Remove the Drain Plug
    • Use your socket wrench to unscrew the transmission drain plug underneath the case.
    • Allow the old oil to completely drain into your pan. Expect the process to take several minutes.
    • Inspect the removed drain plug and its gasket/O-ring for damage. Replace as needed.
  • Clean/Replace the Oil Filter or Screen
    • On the IT250, check for an oil filter cover or screen. Two-stroke models often use a cleanable wire mesh screen rather than a paper oil filter.
    • If equipped, remove the oil filter cover (usually secured by three bolts), then take out the old filter or screen.
    • Clean the screen thoroughly with a lint-free rag and inspect for debris. Replace with a new filter if yours is the replaceable type.
    • Reinstall the clean (or new) screen/filter and secure the cover, ensuring the sealing surface and gasket are clean and undamaged.
  • Reinstall the Drain Plug
    • Once oil is fully drained and the filter situation sorted, replace the drain plug with the (new) gasket or O-ring if needed.
    • Tighten gently but firmly—avoid overtightening which could strip threads in the crankcase.
  • Add New Oil
    • Transmission oil capacity (change): Refer to your owner’s manual for the precise volume. For most IT250s, it is generally around 650cc (0.65 liters) to 700cc (0.7 liters), but always check the manual for your specific configuration.
    • Using a funnel to avoid spills, pour in the recommended oil type (SAE 10W/30 “SE”).
    • Check the oil level using the sight glass or dipstick, if equipped. Add more if necessary, but do not overfill.
  • Run and Inspect
    • Replace the transmission filler plug and start the engine. Let it run for a few minutes, shifting through gears to circulate new oil.
    • Shut the engine off and re-check oil level, topping up if needed.
    • Inspect for any leaks around the drain plug and oil filter cover.
    • Dispose of the old oil at a recycling center or auto parts store—never pour it down the drain.

Specific Model Call-Outs for 1981 Yamaha IT250 Owners

  • This model uses separate oil for the transmission and premixed fuel/oil for the engine. Be sure you are changing the correct cavity—engine transmission oil only, NOT the two-stroke autolube reservoir or fuel mixture.
  • The drain plug and filler locations are unique to the IT250, positioned above and below the kick starter.
  • If you replaced or cleaned a reusable oil filter screen, inspect for significant wear or metallic shavings as these could be signs of transmission issues.
  • Always double-check torque specs in the owner’s manual—over-tightening can crack the case or strip threads.
  • Because the IT250 is now a vintage classic, take extra care with aged fasteners and gaskets that may have become brittle over time. If in doubt, replace them.

Final Notes

  • Use only high-quality, brand-name oils that meet or exceed the manufacturer’s rating (SAE 10W/30 SE or modern updated equivalents).
  • Establish a regular maintenance schedule—oil changes should occur every 10-20 operating hours depending on riding conditions, or at least once per season.
  • Proper oil changes will extend the life of your IT250 and help you enjoy trouble-free riding on- or off-road.

This guide is proprietary content developed for MotoSport.com and is intended for educational and informational use by our riding community.

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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.