To adjust the high and low settings on a Stihl chainsaw, you'll need to access the carburetor and use a small screwdriver to make the adjustments. Please note that carburetor adjustments should only be made by individuals who are familiar with small engine mechanics, as improper adjustments can damage the engine or lead to unsafe operation. If you're not confident in making these adjustments yourself, it's best to take your chainsaw to a qualified service technician.
Here's a general guideline for adjusting the high and low settings on a Stihl chainsaw:
Locate the Adjustment Screws: The carburetor adjustment screws are typically located on the side of the chainsaw's housing. The high-speed adjustment screw is usually marked with an "H" or "HI," while the low-speed adjustment screw is marked with an "L" or "LO."
Identify the Initial Settings: Before making any adjustments, find out the recommended initial settings for the carburetor screws from the user manual or the Stihl website. These initial settings will provide a baseline for adjustments.
Warm Up the Chainsaw: Start the chainsaw and let it warm up for a few minutes to reach operating temperature. Ensure the chain brake is engaged during the adjustment process.
Adjust the Low-Speed Screw (L): To adjust the low-speed setting, turn the L screw clockwise until it lightly seats (don't overtighten), and then back it out 1.5 to 2 turns. This is the starting point for the low-speed adjustment.
Adjust the High-Speed Screw (H): To adjust the high-speed setting, turn the H screw clockwise until it lightly seats, and then back it out 1.5 to 2 turns. This is the starting point for the high-speed adjustment.
Fine-Tune the Settings: With the initial settings in place, you can now fine-tune the carburetor. Gradually turn the high-speed screw (H) clockwise until the engine runs smoothly at full throttle without hesitation or excessive smoke. Then, do the same with the low-speed screw (L) to achieve smooth idling without stalling.
Check for Proper Adjustment: After making adjustments, test the chainsaw's performance by revving the engine at full throttle and then releasing the throttle quickly. The engine should quickly return to idle without stalling or sputtering.
Check the Chain: Ensure the chain stops moving when the throttle trigger is released, and the engine is idling.
Remember that carburetor adjustments can significantly affect the chainsaw's performance and should be made with caution. If you're unsure or encounter difficulties, it's best to seek the assistance of a professional Stihl service center or a qualified chainsaw technician.