If a lawnmower emits black smoke, the cause is not obvious at first glance. This guide accompanies you through the root cause analysis with practical tips on common sources of error and effective countermeasures. This can be the reason for a lawn mower emitting black smoke.
Dirty spark plugs or the carburetor can be the reason for the lawn mower emitting black smoke
Cause: Sooty spark plug
Sooted spark plugs are one of the top 3 most common causes of black smoke. The more dirt particles accumulate on it, the more intensely it smokes. If you don't intervene now, the lawnmower will ultimately not start at all. Here's how to get rid of the problem:
- Park the lawnmower and let it cool down
- Disconnect the connector from the spark plug
- Unscrew the spark plug with the spark plug wrench
Now clean the spark plug and contacts with a brush and cloth. Please do not use water or liquid cleaning agents for this purpose. Then put the clean spark plug back in and put the connector on it.
Cause: Clogged air filter
Black smoke is a typical symptom of a dirty and clogged air filter. If you can identify this component as the culprit, either cleaning will fix the problem or you can replace the filter. Your lawnmower's owner's manual tells you how to remove the air filter.
If it is a paper filter, you can knock out the dirt or blow it out with compressed air. Foam filters can be cleaned very easily with warm water and washing-up liquid.
Cause: Dirty carburetor
If you suspect a dirty carburetor as the cause of black smoke, you do not necessarily have to remove the component. With a little luck, the problem can be overcome with the following emergency aid program:
- Pull spark plug connector
- Drain gasoline from the tank
- Disconnect and clean the line between the tank and the carburetor
Spray all accessible nozzles, throttle valves and the entire housing with a carburetor cleaner. The spray not only removes dirt deposits, but also grease, oil and resin. We also recommend an oil change. Reassemble the lawn mower and do a test run. Experience has shown that black smoke no longer rises.
tips
If a lawnmower smokes blue, the cause is leaking oil. Check the oil level carefully. Spilled gasoline is also a possible trigger. White-blue smoke rises just as often if you previously tilted the lawn mower in the wrong direction for cleaning work.