Step 1 - Clean the Air Filter

When cleaning a carburetor of a chainsaw, check the air filter first. A clogged or dirty filter will prevent needed air from being drawn into the carburetor's combustion chamber. If it's metal, it can be cleaned by swishing with liquid cleaning agent. If the filter is made of paper or other material, you will probably need to replace it.

Step 2 - Clean Carburetor Intake Components

Once your air filter has been replaced or cleaned and all the saw's parts are in place, try starting it again. If it still won't start, you'll then need to check the air intake surfaces for a gummy residue. This residue is typically gold or brown in color and should be easily visible on the surface of air intake components. If you spot this kind of residue you should be able to clean it easily by spraying the gummed surface with a spray cleaner.

Step 3 - Clean Carburetor Needle Valves

After doing the first two steps, if you still have problems in starting the chainsaw, check the carburetor's needle valves that may also be gummed up by fuel deposits. Any of these deposits left in the carburetor can usually be dissolved by fuel added to the fuel in the saw's gas tank.

Step 4 - Operate the Pull Cord

Give your pull cord several strong pulls and alternate with several pauses. Sometimes this cleaning requires a flow of fuel with the cleaning agent in it over these gummed up surfaces. Even though the saw may not be running yet, just pulling the cord, when combined with a few rest intervals, it can move the cleaning agent through the carburetor valves enough to clean off any residue left on their surfaces.

Step 5 - Use Fresh Fuel

Sometimes the problem may be caused by old fuel or fuel into which moisture has condensed and contaminated the old fuel. At that time, you should empty the old gasoline from the tank and refill it with fresh gas.

If all this cleaning fails to correct the starting problem, you may have no other choice but to take the saw to a small engine shop where mechanics have been trained to repair chainsaws