The carburetors on new Echo chain saws come adjusted from the factory. However, due to different environmental factors, such as altitude, the carburetors may not stay properly set for long. When that happens, even a newer chain saw will need its carburetor adjusted. However, Echo recommends running the chain saw through at least two full tanks of gas before adjusting the carburetor. Overadjusting the carburetor on a new saw can also lead to serious engine damage, with the potential to ruin your new saw.
Things You'll Need
Approved fuel container
Fresh Echo chain saw fuel
Unscrew the top cylinder cover on the Echo chain saw, using the screwdriver. Take the cover off and pull the air filter element off the saw. Brush off the air filter element to make sure it's clean.
Open the approved fuel container and mix up a fresh batch of chain saw fuel, using a 50-to-1 ratio of gas to two-cycle oil. Close the container and shake up the contents. Fill the Echo's tank with the gas.
Place the Echo on a spot of ground where the chain won't contact anything during carburetor adjustment. Start and run the chain saw at a high idle for several minutes to warm it up.
Remove the grommet covers from the low- and high-speed carburetor screws, on the side of the engine. Connect the tachometer to the spark plug wire.
Let the engine idle and check the reading. Adjust the low-speed screw with the small screwdriver until it idles between 2,700 and 3,300 rpm.
Depress the throttle until it is wide open, then check the reading. Adjust the high-speed screw clockwise or counterclockwise until it reaches 10,500 to 11,500 rpm.
Turn the low-speed screw clockwise until the chain starts to spin. Rotate the screw back counterclockwise until the chain stops. Position the low-speed screw to the highest rpm before the chain starts to spin.
Depress the throttle again and make sure the chain saw transfers smoothly from idle to high speed. Check the high-speed and low-speed readings again to make sure they fall within the speed parameters. Readjust as necessary.
Some Echo models may have slightly higher or lower high and low speeds. Always consult your model’s instruction manual before adjusting the carburetor.
Never set the high speed above your model’s maximum rpm, which can damage an engine in less than one minute.