The Echo CS 400 utilizes a two-cycle engine with a Walbro carburetor. A carburetor regulates the quantity of fuel which moves between the fuel tank and the engine while using the chain saw. It may get dirty, greasy and clogged with usage, which then causes problems with sputtering and cutting out. Echo includes carburetor repair kits, also called rebuilding kits, to assist with the cleaning process. Some parts wear with age or are fragile, and may break during cleaning, therefore replacing these would be the easiest option.
Remove the screws in the carburetor base plate. Remove the base plate, bottom and posterior gasket, which might all be pasted together if the device is cluttered. Unscrew the needle and needle lever, being careful not to lose the spring beneath them.
Take out the big screws holding the plate on, and that you’ll find on the other side of the carburetor. Remove the gasket and reed valve, which can be pasted together. Remove the filter screen.
Use a can of carburetor spray with its attached nozzle to clean off any parts which may be stuck with them. Pour the new kit out on a table and then match the previous parts to new ones. Discard the previous parts. Spray the cleaner involving any holes in the primary carburetor piece and about the plates you removed. Lay the pieces out to dry nicely, turning them as they dry to avoid further clogging.
Reassemble the carburetor starting with the filter screen. Press the screen lightly into place to avoid tearing. Place the new gasket and reed valve into place with the cap plate on top. Screw it into position. On the other side, replace the spring, needle and needle lever, and screw them in. Position the new gasket and diaphragm under the base plate and then screw them back into position.