During work, the saw chain expands or contracts. The tension of the saw chain changes. During work, the tension must therefore be checked regularly and adjusted if necessary. The correct procedure is as follows:

• Switch off the pruner and remove the battery.
• Open the handle of the wing nut.
• Turn the wing nut two turns anti-clockwise. The wing nut is loosened.

WARNING: The cutting teeth of the saw chain are sharp. This may result in the user cutting themselves.

• Wear work gloves made of durable material.
• Move the guide bar to the left or right until the drive links of the saw chain are still half visible on the underside of the guide bar.
• Turn the wing nut clockwise until the sprocket cover is firmly attached to the pruner.
• If the saw chain can still be pulled over the guide bar with two fingers and with little effort, it is properly tensioned.
• If the drive links of the saw chain are fully visible on the underside of the guide bar, the chain is too loose. Tension the saw chain again.
• Close the handle of the wing nut.

Pro tip: Dirty chain links can encourage the chain to come off. The chain links can stiffen due to oil deposits, resin and plant sap. Therefore, clean and lubricate the chain regularly before each use. For optimal care, use STIHL Multioil Bio.

Pro tip: A chain that is too tightly tensioned can also come off more easily, increase wear and affect how easily the chain slides over the bar. The chain is optimally tensioned when 1-2 mm of the chain's drive links are visible outside the groove of the guide bar.