Stihl SR 340 SR 420 Instruction Manual
![Stihl SR 340 SR 420 manual cover](/images/e1732d0bc8f55befd4a15e20/thumbs/thumb175x175.webp)
Ensure the fuel tank is filled with the correct fuel mix, set the choke lever to the cold start position, press the fuel pump bulb several times, set the throttle to the start position, and pull the starter rope until the engine fires.
Perform a visual inspection before each use, clean the air filter every 10 hours of operation, replace the spark plug every 100 hours, and conduct a thorough inspection annually.
Check for fuel freshness and proper mixture, ensure the spark plug is clean and properly gapped, inspect the air filter for blockages, and verify that the ignition switch is on.
Use a high-quality 2-stroke engine oil mixed with unleaded gasoline at a ratio of 50:1.
Remove the air filter cover, take out the filter element, wash it in warm soapy water, rinse thoroughly, allow it to dry completely, and reinstall it.
Locate the carburetor adjustment screws, use a screwdriver to adjust the idle speed screw (LA) for stable idling, and adjust the low (L) and high (H) speed screws to achieve optimal performance.
Wear protective clothing, including goggles, gloves, ear protection, and a mask; ensure the area is clear of bystanders and pets; and follow all safety instructions in the user manual.
Drain the fuel tank, run the engine until it stops to clear the carburetor, remove the spark plug, add a few drops of oil into the cylinder, and pull the starter rope to distribute the oil.
Check for loose parts or screws, inspect the fan wheel for damage or imbalance, and ensure the unit is properly balanced and assembled.
Yes, the Stihl SR 340/SR 420 is designed for both liquid and granular applications, but ensure you use the correct nozzles and settings for each type of material.