Chainsaw Engine Dies When Hot

A common problem many people have is a chainsaw engine cutting out when hot. There are many reasons what could be causing this and this guide helps explain the various causes.

Spark Arrestor is Clogged

A spark arrestor screen can get clogged with deposits of carbon from prolonged exposure to sparks. The screen is a metallic wire mesh that prevents sparks exiting the muffler so this part needs to be checked for carbon deposits. If it's clean then that's fine, however if it is clogged it needs to be cleaned with a wire brush or replaced with a new one.

Fuel Filter is Clogged

The fuel filter is designed to filter the fuel so that the gasoline charge supplied to the carburettor is clean and uncontaminated. When the quality of fuel is poor, deposits can form on the fuel filter. When it's clogged, this affects the flow of gasoline to the engine which then causes the engine to stall. The fuel filter will need replacing if it appears to be clogged yet if it seems clean, it may be a different problem causing the engine to cut out.

Air Filter is Dirty

An air filter filters the air before reaching the carburettor so if it's dirty, the carburettor will not make the correct air-fuel mix which causes problems with starting the engine. Check the filter for dirt. If its not too dirty, a soap and water solution can be used to clean it however if it's dirty and doesn't clean up properly even after cleaning it, it may then need to be replaced.

Carburettor is Restricted

A restricted carb is one of the main causes of small engines stalling. They are designed to formulate the air-fuel mixture which is then supplied to the engine for combustion. If fuel is stored in the tank for a certain duration, the quality of fuel can lessen as it forms white deposits in the fuel lines. These in turn can clog the carburettor jets which will impact the fuel flow to the engine.