Smoke from the exhaust outlet While using your hedge trimmer, you may notice light grey smoke from the exhaust outlet (muffler). Reasons for this could be: An incorrect fuel mixture, usually when there is too much oil in the mixture; make sure that you always use the correct fuel mixture for your hedge trimmer. Using an old or stale fuel and oil mixture; always use a fresh fuel and oil mixture; we recommend using Husqvarna fuel and oil for your hedge trimmer. How to mix two-stroke oil and fuel for a hedge trimmer Dirty and restricted air filter; make sure that the air filter on your hedge trimmer is clean and not restricted. How to clean or replace the air filter on your hedge trimmer If the issue persists after using the correct, clean fuel and oil, and the air filter is cleaned, please contact the authorised dealer.