Why Do Lawnmowers Smoke

A lawn mower engine will puff out black smoke when the fuel and air mixture is too rich. Because there isn’t enough air, combustion is incomplete, and the unburnt fuel in the combustion chamber turns to smoke. … If there is still lawn mower smoke, you may have to adjust the carburetor to make a leaner fuel mixture.

How do I stop my lawnmower from smoking?

Try replacing the air filter. (Note: air filters vary by mower model; view example air filter on Amazon.) Next, run your lawn mower for a few minutes. If the black smoke still appears, the carburetor might need to be adjusted in order to increase airflow.

Why is blue smoke coming from my lawn mower?

The mower blows out Blue or White smoke. This is a sign that the engine is burning excess oil. The excess oil in the engine causes incomplete combustion which will create smoke and a carbon buildup.