When the lawnmower spits and smokes out of the blue, the operator is very shocked. The problem often occurs after cleaning or maintenance. You can find out why this is the case here, how you can act correctly now and prevent it in the future.
Why does oil come out of the lawnmower's exhaust?
Oil gets into the exhaust of a lawnmower when it is tilted sharply during maintenance. The crankcase breather leads engine oil into the carburettor, from there into the intake manifold and finally into the exhaust. Clean the spark plug, air filter and mower deck to resolve the problem.
How does the oil get into the exhaust of the lawnmower?
To protect your he alth and the environment, the crankcase ventilation on petrol lawnmowers always leads into the carburettor or the intake manifold. If the mower is tilted sharply when cutting lawns on slopes or for maintenance, engine oil can run from the crankcase into the intake port via the carburettor.
Typical symptoms of the problem include oil leaking from the exhaust and a whitish-blue engine smoking. If a large amount of engine oil has leaked into the carburettor, the engine will be difficult to start. Instead of air, there is oil in the cylinder, so the starting process requires a lot of force.
Cleaning campaign solves the problem – Here’s how it works
If your lawnmower is spitting oil, smoking heavily, and having a hard time starting, you can solve the problem with a full-scale cleaning. How to do it right:
- Close fuel tap
- Pull the spark plug connector, unscrew the spark plug and clean it thoroughly along with all contacts
- Remove and clean the air filter or replace it with a new filter (€4.00 on Amazon)
- Check the oil level and, if necessary, top up with fresh lawnmower oil using a funnel
- Wipe the mower deck with a damp cloth and grease-dissolving cleaner
After this cleaning, do a test run. If there are no more complaints, you can save yourself having to remove and clean the carburettor. If the engine continues to smoke and sputter, you cannot avoid cleaning the carburettor. Numerous manufacturers offer complete repair kits for this purpose that contain all the necessary spare parts.
Tip
To prevent engine oil from running over the carburettor into the exhaust, a lawn mower should always be tilted in the correct direction. If it is unavoidable to lift a petrol mower to the side, the spark plug, air filter and carburettor always point skyward.
