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Let the engine warm up
When starting an engine is cold. It is necessary to wait for the temperature increase before judging whether or not he smokes. Indeed, the settings are made for a hot engine. So don't worry if you see any abnormal fumes when you start. Let it warm up!
Alert, my engine is smoking!
Once the engine is hot, if you see any more smoke, you will have to determine the color. Each one determines a cause of problem:
- Black smoke
- Blue smoke
- White smoke
Black smoke = wrong setting
Black smoke is a sign of poor fuel combustion. It can be a surplus of diesel fuel that arrives in the cylinder: adjustment or stalling of the injection pump, incorrectly calibrated injectors. These black fumes can also come from a lack of air for the engine. It is then necessary to check the condition of the air filter or increase the air supply to the hold.
If it is not pleasant and dirties the transom, this black smoke is the least serious of the 3 colours. Repairs will be limited to adjustments that should not result in deep opening of the engine. This is not the case in the other 2 situations...
Blue smoke = the engine "eats" oil
Blue smoke indicates that oil is entering the combustion chamber. This is usually a sign of worn scraper rings. This is not a good sign, because the repair requires the removal of the entire top engine... This oil that burns as blue smoke comes from the lubricating oil. If the smoke is very present, you should see your engine oil level drop after a navigation.
White smoke = the engine "swallows" water
A boat motor is cooled by water. The latter circulates in ducts all around the engine to cool it. But if a gasket does not do its sealing job, water can end up in the combustion chamber. It ends in water vapour and exits through the exhaust in the form of white smoke. It is usually at the cylinder head gasket that the problem occurs. No other choice than to go to a mechanic...
