MIXTURE SUPPLY MEANS OF MOTORCYCLE

PURPOSE:To improve the measuring accuracy of the quantity of suction air by a hot-wire air flow meter by positioning a blow-bye gas inlet port which is communicated to a crankcase of an engine, in the vicintity to the inlet side of a throttle chamber which tands away from an outlet of a suction cylinder. CONSTITUTION:An air cleaner chamber 12 consists of a right suction cylinder 15, a casing which encloses it and contains an air cleaner element 21 and a collection chamber 17 which is connected to a throttle chamber 10 and has a blow-bye gas inlet port 19. Said inlet port 19 is positioned in the vicinity to the joint of the collection chamber 17 and the throttle chamber 10. Blow-bye gas from a crankcase is fed to an area as apart as possible from the outlet of the suction cylinder 15 so as to reduce a variation of air flow velocity inside the suction sylinder 15, whereby a hot-wire probe 13 which is disposed inside a bypass passage 14 may accurately detect the quantity of suction air.