Replacing the gear oil on your Honda CR250 is a fairly easy and economical do-it-yourself repair that will save you a few dollars. Gear oil is a lubricating motor oil made specifically for transmissions and differentials of motorcycles and heavy trucks. While similar to motor oil, it has a higher viscosity to protect moving parts. In use, gear oil does not reach the high temperatures that engine oil reaches. It is recommended to regularly change gear oil. Failure to do so could result in damage to your CR250's clutch system.
Start your CR250 and allow it to warm up. Once it's warmed up (after about 5 minutes), kill the engine.
Place an oil dripping pan underneath the engine, then remove the drain plug. The drain plug for the gear oil is located underneath the engine toward the centre. Use pliers if you cannot unscrew the plug with your fingers.
Pull the clutch lever in and secure it with a cable tie. This allows the gear oil to drain from between the plates of your CR250 clutch.
Drain for five minutes, then replace the gear oil drain plug.
Refill with the correct amount of light gear oil, approximately 650cc, as is marked by the filler hole on your Honda CR250. Release the clutch lever.