RedMax CHT220 Owners Manual - Page 16

CHT220/CHT220L 9. Maintenance ■ CARBURETOR Adjustment of the idle speed Before any adjustments are made, make sure that the air filter is clean and the air filter cover is fitted. Make sure the start throttle position is disengaged. Adjust the idle speed using the idle adjustment screw T, if it is necessary to readjust. First turn the T screw clockwise until the cutting attachment starts to move. Then turn the screw anticlockwise until the cutting attachment stops. The idle speed is correctly adjusted when the engine runs smoothly in every position. The idle speed should also be well below the speed at which the cutting attachment starts to move. Rec. idle speed: See the Technical data section. be cleaned or replaced if necessary once a week. If the mesh is damaged it must be replaced. If the mesh is frequently blocked, this can be a sign that the carburetor is incorrectly adjusted or that too much oil has been mixed with the petrol. On mufflers fitted with a catalytic converter, the mesh must be checked, and if necessary cleaned, monthly. If the mesh is damaged it must be replaced. If the screen is frequently blocked, this can be a sign that the performance of the catalytic converter is impaired. Contact your dealer to inspect the muffler. A blocked screen will cause the machine to overheat and result in damage to the cylinder and piston. CAUTION! Never use a machine with a defective muffler. WARNING! Mufflers fitted with catalytic converters get very hot during use and remain so for some time after stopping. This also applies at idle speed. Contact can result in burns to the skin. Remember the risk of fire! WARNING! If the idle speed cannot be adjusted so that the cutting attachment stops, contact your dealer/service workshop. Do not use the machine until it has been correctly adjusted or repaired. ■ MUFFLER ■ COOLING SYSTEM To keep the working temperature as low as possible the machine is equipped with a cooling system. CAUTION! Some mufflers are fitted with a catalytic converter. See chapter on Technical data to see whether your machine is fitted with a catalytic converter. The muffler is designed to reduce the noise level and to direct the exhaust gases away from the operator. The exhaust gases are hot and can contain sparks, which may cause fire if directed against dry and combustible material. The cooling system consists of: 1 Cooling fins on the cylinder. 2 Cylinder cover (directs cold air over the cylinder). 3 Air intake through the crankcase (inside the tank). Clean the cooling system with a brush once a week,more often in demanding conditions. A dirty or blocked cooling system results in the machine overheating which causes damage to the piston and cylinder. Some mufflers are equipped with a special spark arrestor mesh. If your machine has this type of muffler, the mesh must be cleaned. This is best done with a wire brush. On mufflers without a catalytic converter, the mesh should US-14