Patent ID: 8555831

Claim:
A method for operating a two-stroke engine, said two-stroke engine configured as a single cylinder engine having a cylinder defining a combustion chamber; said combustion chamber being delimited by a piston; said piston being configured to drive a crankshaft rotatably mounted in a crankcase; said crankcase being connected to said combustion chamber at least at one position of said piston via a transfer channel; said two stroke engine having an inlet into said crankcase and an outlet out of said combustion chamber; said two-stroke engine further having an arrangement configured to supply fuel, a control and a device determining crankcase pressure (p KGH ) during engine cycles of said engine; said method comprising the steps of: determining said crankcase pressure (p KGH ) for each engine cycle; determining a mean value (p M ) of said crankcase pressure (p KGH ) from a plurality of values for said crankcase pressure (p KGH ) measured during previous engine cycles; in each one of said engine cycles, determining a fluctuation in said crankcase pressure (p KGH ) determined in said one engine cycle as a difference between said determined crankcase pressure (p KGH ) and said mean value (p M ) of said crankcase pressure (p KGH ); and, determining whether a combustion occurred during each engine cycle by comparing said difference to a limit value (Δp limit ).