4282 025 1901 – STIHL Exhaust Valve Genuine OEM Part4282 025 1901 STIHL Exhaust Valve Genuine OEM Part Fits: BR 500 BR 550 BR 600 (Engine Assembly) The STIHL Exhaust Valve 4282 025 1901 is a genuine OEM replacement engine component designed for select STIHL backpack blowers. This exhaust valve plays a critical role in the engines exhaust system by allowing burned gases to exit the combustion chamber efficiently, supporting proper airflow and engine performance. Over time, exhaust valves may wear,