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 (104) including an internal combustion engine (204) with a crankshaft (304); an assembly for supplying cleaned air and fuel to the engine, having an upstream air inlet; a fan housing (404) located in an outer end of said tool unit and having an air inlet for ambient air; a fan wheel (302) arranged in the fan housing (404); the fan wheel (302) driven by the crankshaft (304) to supply cooling air, sucked in through the air inlet to cool the engine (204); a combustion air duct (406) having a combustion air intake opening (408) located radially outside of the fan wheel (302) leads the combustion air to the assembly for supplying cleaned air and fuel to the engine via a possible air filter (402). Special shielding elements (410, 412, 414) are used to steer away air and especially particles in the air from said combustion air intake opening (408) to provide a strong cleaning effect of the combustion air in said combustion air duct (406).