12Be sure to use genuine MAKITA metal blades or nyloncutting head.The metal blade must be well polished, free of cracks or breakage. If the–metal blade hits against a stone during operation, stop the engine and checkthe blade immediately.Polish or replace the metal blade every three hours of operation.–If the nylon cutting head hits against a stone during operation, stop the–engine and check the nylon cutting head immediately.CAUTION: The appropriate protector must always be installed, for your ownsafety and in order to comply with accident-prevention regulations.Operation of the equipment without the guard being in place is notpermitted.The outside diameter of the cutter blade must be 300 mm (12”)or less. Never use any blades exceeding 300 mm (12”) in outsidediameter.Turn the machine upside down, and you can replace the metal blade or nyloncutting head easily.Insert the hex wrench through the hole in the gear case and rotate the–receiver washer (4) until it is locked with the hex wrench.Loosen the nut (1) (left-hand thread) with the socket wrench and remove the–nut (1), cup (2), and clamp washer (3).(4)(3)(2)(1)(4)(3)(2)(1)RotationHex wrenchMOUNTING OF METAL BLADE OR NYLON CUTTING HEADMounting of metal blade with the hex wrench still in placeMount the metal blade onto the shaft so that the guide of the receiver washer–(4) fits in the arbor hole in the metal blade. Install the clamp washer (3), cup(2), and secure the metal blade with the nut (1).[Tightening torque: 20 - 30 N-m]NOTE: Always wear gloves when handling the metal blade.NOTE: The metal blade-fastening nut (with spring washer) is a consumablepart. If there appears any wear or deformation on the spring washer,replace the nut.Mounting of nylon cutting headThe clamp washer (3), cup (2), and nut (1) are not necessary for mounting–the nylon cutting head. The nylon cutting head should go on top of thereceiver washer (4).Insert the hex wrench through the hole in the gear case and rotate the–receiver washer (4) until it is locked with the hex wrench.Then screw the nylon cutting head onto the shaft by turning it counter-–clockwise.Remove the hex wrench.–Hex wrenchLoosen TightenHex wrench