Subaru SX21 User Instructions
![Subaru SX21 Engine manual cover](/images/qHrjkZxTeSWveSkUUoQmUkjE/thumbs/thumb175x175.webp)
The recommended oil type for the Subaru SX21 engine is SAE 10W-30 for general use. In colder climates, SAE 5W-30 can be used for better cold start performance.
It is recommended to change the oil every 50 hours of operation or at least once per season, whichever comes first.
The proper spark plug gap for the Subaru SX21 engine is 0.028 to 0.031 inches (0.7 to 0.8 mm).
If the engine won't start, check for fuel supply, ensure the spark plug is clean and properly gapped, and verify that the ignition switch is on. Also, inspect the air filter for dirt and debris.
To clean the air filter, remove the air filter cover, take out the filter, and clean it with compressed air or wash it with mild detergent and water. Dry it completely before reinstalling.
To adjust the idle speed, locate the idle adjustment screw on the carburetor and turn it clockwise to increase the speed or counterclockwise to decrease it. Use a tachometer to measure the engine's RPM for accuracy.
If the engine overheats, stop the engine immediately and allow it to cool. Check the oil level and cooling fins for obstructions. Ensure proper ventilation around the engine.
To winterize the engine, drain the fuel system, change the oil, remove the spark plug, and add a few drops of oil into the cylinder. Pull the starter cord slowly to distribute the oil, and reinstall the spark plug.
Perform regular maintenance every 50 hours, including oil changes, air filter cleaning, and spark plug inspection. Annually, replace the spark plug and check the fuel system for leaks.
Ensure the air filter is clean, use the recommended oil type, maintain proper tire pressure if applicable, and avoid overloading the engine. Regular maintenance will also help maintain fuel efficiency.