MAINTENANCE18 – EnglishCooling systemTo keep the working temperature as low as possible themachine is equipped with a cooling system.The cooling system consists of:1 Air intake on the starter.2 Fins on the flywheel.3 Cooling fins on the cylinder.4 Cylinder cover (directs cold air over the cylinder).Clean the cooling system with a brush once a week, moreoften in demanding conditions. A dirty or blocked coolingsystem results in the machine overheating which causesdamage to the piston and cylinder.Spark plugThe spark plug condition is influenced by:• Incorrect carburetor adjustment.• An incorrect fuel mixture (too much or incorrect typeof oil).• A dirty air filter.These factors cause deposits on the spark plugelectrodes, which may result in operating problems andstarting difficulties.If the machine is low on power, difficult to start or runspoorly at idle speed: always check the spark plug firstbefore taking any further action. If the spark plug is dirty,clean it and check that the electrode gap is 0.020 inch (0.5mm). The spark plug should be replaced after about amonth in operation or earlier if necessary.CAUTION! Always use the recommended spark plugtype! Use of the wrong spark plug can damage the piston/cylinder. Check that the spark plug is fitted with asuppressor.Air filterThe air filter must be regularly cleaned to remove dustand dirt in order to avoid:• Carburettor malfunctions• Starting problems• Loss of engine power• Unnecessary wear to engine parts• Excessive fuel consumption.Clean the filter every 25 hours, or more regularly ifconditions are exceptionally dusty.Cleaning the air filterRemove the air filter cover and take out the filter. Wash itclean in warm, soapy water. Ensure that the filter is drybefore refitting it.An air filter that has been in use for a long time cannot becleaned completely. The filter must therefore be replacedwith a new one at regular intervals. A damaged air filtermust always be replaced.1324