To effectively use Computational Fluid Dynamics (CFD) for engine emission development it is necessary to be able to simulate the scavenging flow in an engine. The CFD model for a stratified charged two-stroke engine is even more complex. This model have been tuned and finally validated with engine tests.A CFD model has been made of the Husqvarna 560XP two-stroke stratified charged chainsaw engine. The model contains piston, cylinder, inlet system ducting and exhaust silencer. The simulation runs with moving deforming mesh with all ports active.The airflow levels have been fine tuned with inlet restrictions similar to those in the air filter holder, which is not completely included in the present model.The results and behaviour of the CFD model has a very good match to the measured values of the finished product. This gives us confidence in the model and several aspects can now be studied that is virtually impossible to capture by other means.