35Trouble shootingMalfunction System Observation CauseChain does not run Chain brake Engine runs Chain brake actuated.Engine does notstart or only withdifficultyIgnition system Ignition spark Malfunction in fuel supply system, compressionsystem, mechanical malfunction.No ignition spark STOP switch in position, fault or short‑circuitin the wiring, Spark plug cap or spark plugdefectiveFuel supply Fuel tank is filled Combination switch in Choke position, carburetordefective, suction head dirty, fuel line bent orinterrupted.CompressionsystemInside Cylinder base packing ring defective, radialshaft packings defective, cylinder or piston ringsdefectiveOutside Spark plug does not seal.MechanicalmalfunctionStarter does not engage Spring in starter broken, broken parts inside theengine.Warm startdifficultiesCarburetor Fuel tank is filledIgnition sparkWrong carburetor adjustment.Engine starts, butdies immediatelyFuel supply Fuel tank is filled Wrong idling adjustment, suction head orcarburetor dirty.Tank venting defective, fuel line interrupted,cable defective, Combination switch defectiveInsufficient power Several systemsmay be involvedsimultaneouslyEngine is idling Air filter dirty, wrong carburetor adjustment,muffler clogged, exhaust channel in cylinderclogged, spark arrester screen clogged.No chain lubrication Oil tank/pump No oil on the chain Oil tank empty.Oil guide groove dirty.Oil‑pump adjusting screw incorrectly adjusted.