Patent ID: 6851402

Claim:
A method for operating a two-stroke engine for a portable handheld work apparatus including a motor-driven chain saw, cutoff machine, brushcutter or the like, the two-stroke engine including: a cylinder having a cylinder wall and defining a longitudinal center axis; a piston mounted in said cylinder to undergo a reciprocating movement along a stroke path between top dead center and bottom dead center during operation of said engine; said cylinder and said piston conjointly delimiting a combustion chamber; a crankcase connected to said cylinder; a crankshaft rotatably mounted in said crankcase; a connecting rod connecting said piston to said crankshaft to permit said piston to drive said crankshaft as said piston reciprocates in said cylinder; an outlet for conducting exhaust gas from said combustion chamber; an inlet through which combustion air is conducted into said engine; said longitudinal center axis lying in a center plane partitioning said outlet and said inlet approximately at the center thereof; and, at least three transfer channels connecting said combustion chamber to said crankcase at pregiven control times; the method comprising the steps of: injecting fuel into the region of one of said transfer channels at pregiven control times; transfer synchronously injecting a first component quantity of fuel in at least one rpm range with said first component quantity being metered for a combustion in said combustion chamber; making a second component quantity of fuel ready from at least one preceding injection cycle with said second component quantity passing into said combustion chamber from said crankcase; and, wherein the ratio of said component quantities to each other is adapted in dependence upon rpm and/or load.