Why is my engine hunting?

What is engine hunting?

"Hunting" is when your engine speeds up and slows down in a regular cycle.

Why does hunting happen?

The most common cause for engine hunting is a blockage in the carburettor.

Put simply, this restricts the fuel flow in the carburettor causing the engine to slow down. To try to compensate for this, the engine's governor opens the throttle to allow more fuel into the engine. This speeds the engine up, so the governor tries to slow the engine down and so the cycle begins again.

Although less likely, hunting can also be caused by a separate problem with the governor system.

Why do blockages occur in the carburettor?

The cause of the blockage is minute particles from the fuel tank getting into the carburettor. This can be prevented by ensuring that dirty fuel doesn't enter the fuel tank while the cap is open during fuel filling.

How do I fix engine hunting?

Due to the nature and possible causes of hunting, we would recommend that a hunting fault is professionally diagnosed and repaired by your local garden machinery dealer.