Common Trouble Shooting Issues When Your Chainsaw Engine Dies at Full Throttle but Will Idle

The carburettor, fuel lines, fuel filter, air filter and muffler are all parts that need checking if your engine dies at full throttle. This is a general guide on what could be the cause and advice, however for a more detailed information on your specific model, please refer to the owners manual.

Carburettor

A carburettor mixes fuel and air in the correct ratio - Combustion occurs and then the chainsaw runs. When old fuel sits in it over a long period of time, the carb can become clogged and the chainsaw will then not function correctly. If the carb is damaged or has internally corroded, this will need replacing.

Air Filter

Air filters can become clogged when dirt and debris build up. An air filter protects your chainsaw from the dirt and debris by filtering it out before it reaches the engine but if it clogs, the engine wont have enough air to work properly. In this scenario, the air filter will more than likely be partially clogged so enough air can get to the engine to run on idle but there wont be enough for full throttle. They need to be cleaned regularly to avoid this happening. Clean and replace the air filter if necessary which is located on top of the carburettor.

Fuel Filter

Similar to the air filter, a fuel filter protects the engine from dirt and debris. If it becomes clogged, the fuel wont reach the engine for it to run properly. The fuel filter is only partially clogged if the chainsaw will idle but then dies when going up to full power. To solve this problem, disconnect the fuel filter from the fuel lines and either clean or replace the filter.

Muffler

Carbon deposits can build up in the exhaust port, muffler or spark arrestor when your chainsaw has been running on full throttle over time. This can make one (or more) of these parts become clogged. If this happens, the chainsaw will die as the exhaust gasses cannot exit the engine. This should be replaced and this type of carbon build up should be visible.

Fuel Lines

When a chainsaw is running, fuel travels from the fuel tank to the carb through the fuel lines. If a fuel line is blocked or has a small crack, this can let air into the fuel line and can cause fuel to leak, so the engine cannot run at full power. When replacing fuel lines, disconnect them from the fuel filter and carb and simply replace.