US-15BCZ250S/BCZ260S/BCZ260TSUS■ SPARK PLUG• Starting failure and mis-firing are oftencaused by a fouled spark plug. Cleanthe spark plug and check that the pluggap is in the correct range. For areplacement plug, use the correct typespecified by RedMax. (MA4)• REPLACEMENT PLUG IS A NGKBPMR8Y.• Note that using any spark plug otherthan those designated may result in theengine failing to operate properly or inthe engine becoming overheated anddamaged.• To install the spark plug, first turn theplug until it is finger tight, then tighten ita quarter turn more with a socketwrench.TIGHTENING TORQUE:126~185 in-lbs(14.7~21.6 N.m.)■ MUFFLER• Inspect periodically, the muffler forloose fasteners, any damage orcorrosion. If any sign of exhaustleakage is found, stop using themachine and have it repairedimmediately.• Note that failing to do so may resultin the engine catching on fire.■ SPARK ARRESTER• The muffler is equipped with a sparkarrester to prevent red hot carbon fromflying out of the exhaust outlet.Periodically inspect and clean asnecessary with a wire brush.In the State of California it is requiredby law (Section 4442 of the CaliforniaPublic Resources Code) to equip aspark arrester when a gas powered toolis used in any forest covered, brushcovered, or grass covered unimprovedland. (MA5)(1) spark arresterWARNINGIMPORTANT• Make sure that the engine hasstopped and is cool beforeperforming any service to themachine. Contact with movingcutting attachment or hot mufflermay result in a personal injury.■ AIR FILTERThe air filter must be regularly cleaned toremove dust and dirt in order to avoid:• Carburetor malfunctions• Starting problems• Loss of engine power• Unnecessary wear to engine parts• Excessive fuel consumption.Clean the filter every 25 hours, or moreregularly if conditions are exceptionallydusty. (MA2a)(1) felt (2) urethaneCleaning the air filter:Close the choke valve by moving thechoke control up. (MA2b)(3) choke lever• Remove the air filter cover and take outthe filter. Wash it clean in warm, soapywater. Clean also the inside of the filtercover by using air or a brush. Ensurethat the filter is dry before refitting it.• Remove the Felt filter from the filterholder and gently brush debris from thefilter. An air filter that has been in usefor a long time cannot be cleanedcompletely. The filter must therefore bereplaced with a new one at regularintervals. A damaged air filter mustalways be replaced. Damaged, verydirty, or fuel-soaked air filter mustalways be replaced.■ FUEL FILTER• When the engine runs short of fuelsupply, check the fuel cap and the fuelfilter for blockage. (MA3)(1) fuel filterWARNING.025 in0.655mmMA4(1)MA59. Maintenance(1)(2)MA2a(3)MA2b(1)MA3