Method of running a four-stroke spark-ignition engine

摘要

Method of running a four-stroke spark-ignition engine with not specially hardened seats for the exhaust valves, using an unleaded carburettor fuel which contains 1 to 100 ppm, preferably 5 to 20 ppm, of ferrocene (bis- pi -cyclopentadienyl iron). Due to the addition of the ferrocene readily soluble in fuel, the exhaust valves are protected from excessive wear even at increased speeds and under more severe running conditions.