Throttle adjustment device for brush cutter

According to one embodiment, a throttle adjustment device, for a brush cutter in which an engine is mounted at one end of a handle pipe (1) and in which a throttle adjustment wire (4, 4-2) extends from a throttle of the engine, include: a throttle lever (7) having an operation portion (7-1) to be operated by the user; a sub lever (8) having a holding portion (8-1) to be connected with an extending end of the throttle adjustment wire (4, 4-2); a case (3) to be fixed to the handle pipe (1), the throttle lever (7) and the sub lever (8) being rotatably mounted in the case (3); and a connecting member (10) configured to bring the throttle lever (7) and the sub lever (8) into: an interlocked state where the throttle is adjustable in accordance with an operation amount of the throttle lever (7); or an un-interlocked state where the throttle is not adjustable regardless of the operation amount of the throttle lever (7).