A portable, hand-held, combustion engine powered working machine, e.g. a power cutter, chain saw or trimmer, comprising: a tool unit including a working tool; a machine unit including an internal combustion engine with a crankshaft; an assembly for supplying cleaned air and fuel to the engine, having an upstream air inlet; a fan housing located in an outer end of the machine unit and having an air inlet for ambient air; a fan wheel arranged in the fan housing; the fan wheel driven directly or indirectly by the crankshaft to supply cooling air, sucked in through the air inlet to cool the engine; a combustion air duct having a combustion air intake opening located radially outside of the fan wheel leads the combustion air to the assembly for supplying cleaned air and fuel to the engine via a possible air filter (236, 238; 402), at least one shielding element (410, 412, 414) is / are used to steer away air and especially particles in the air from said combustion air intake opening to provide a strong cleaning effect of the combustion air in said combustion air duct, and a first shielding element is arranged in the form of a deflector attached to said combustion air intake opening and running in an essentially longitudinal direction, i.e. in the direction of the crankshaft, characterised in that said deflector has an essentially flat or concave outer side, the deflector is attached to an inner side of the combustion air intake opening which is the side which is closest to the fan wheel, wherein a deflector line along the deflector outer side extending outwards clears, i.e. does not meet the leading edge of the outer side of said combustion air intake opening. a tool unit including a working tool; a machine unit including an internal combustion engine with a crankshaft; an assembly for supplying cleaned air and fuel to the engine, having an upstream air inlet; a fan housing located in an outer end of the machine unit and having an air inlet for ambient air; a fan wheel arranged in the fan housing; the fan wheel driven directly or indirectly by the crankshaft to supply cooling air, sucked in through the air inlet to cool the engine; a combustion air duct having a combustion air intake opening located radially outside of the fan wheel leads the combustion air to the assembly for supplying cleaned air and fuel to the engine via a possible air filter (236, 238; 402), at least one shielding element (410, 412, 414) is / are used to steer away air and especially particles in the air from said combustion air intake opening to provide a strong cleaning effect of the combustion air in said combustion air duct, and a first shielding element is arranged in the form of a deflector attached to said combustion air intake opening and running in an essentially longitudinal direction, i.e. in the direction of the crankshaft, characterised in that said deflector has an essentially flat or concave outer side, the deflector is attached to an inner side of the combustion air intake opening which is the side which is closest to the fan wheel, wherein a deflector line along the deflector outer side extending outwards clears, i.e. does not meet the leading edge of the outer side of said combustion air intake opening.