A chainsaw, when properly adjusted, should accelerate smoothly when the engine speed is increased and should not emit excessive smoke. When the carburetor is improperly adjusted or the saw is old and the carburetor is out of adjustment, it can emit large amounts of smoke when you are using it. Improper carburetor adjustment can also reduce the life of the chainsaw engine. Learn how to adjust it so that it runs smoothly and efficiently.
Check the fuel level in the fuel tank. It should be at least half full. If you have less fuel, it will be more difficult to make proper adjustments to the carburetor.
Access the carburetor on your chainsaw. Its location may vary according to the model and manufacturer of your specific chainsaw. Generally, you’ll need an adjustable wrench and a set of hex keys to remove the bolts from the chainsaw’s cover. Remove the cover. The carburetor fittings are small bolts near the engine.
Start the chainsaw engine and wait three minutes. This allows time for the engine to warm up, as this is necessary to properly adjust the carburetor.
Turn the adjustment screw. As you do, you will hear the engine speed increase or decrease. Adjust it so that it runs at a high speed. This will prevent accidental stalling.
Adjust the low speed adjustment screw. Turn it to one side until the motor starts to run rough. Then turn it the other way until the motor starts to run rough. Mentally note the two positions and turn the screw so that it is in the middle of those two points. Slightly pull the trigger on the chainsaw to check if you have set the speed to low.
Squeeze the trigger to set the chainsaw to full speed. If the engine sound is smooth but with a slight rasping sound, the high speed setting is correct. If the sound is fast and sluggish, adjust the screw and pull the trigger again. Repeat the process until the chainsaw speed sounds smooth.
Replace the chainsaw cover.
Tips
Carburetor adjustments can be made while in use, so readjust as needed.
Warnings
Always stand with your feet firmly on the ground when handling a running chainsaw.