Aircraft piston engines are built with compromise on performance and safety. The desire to achieve the highest power-to-weight ratio leads to the search for solutions that optimize the combustion process. On the other hand, the need for maximum reliability leads to the simplification of the design at the costs of performance. An example of such a compromise is the ignition system of the ASz-62IR engine. In this engine there is a double magneto ignition system with a fixed ignition advance angle. As part of the modernisation of this engine, an electronically controlled dual ignition system was developed, which allows for optimum control of the ignition advance angle in terms of power. This article discusses the results of bench tests of the ASZ-62IR-16X engine with fixed ignition timing and variable timing control. Functional parameters and toxicity of exhaust gases were analyzed.