<div class="htmlview paragraph">The paper deals with the effect of some design and controlling parameters of a prechamber engine on combustion and operation. The lowest delay in the working mixture ignition, the highest rate and completeness of the burning, the widest stability limits for combustion of lean mixtures, the lowest octane requirements and emission toxicity are obtained only within definite changes in prechamber and combustion chamber volumes (2-3%), in the overall outlet channel cross-section area (0.03-0.04 cm²/cm³ of prechamber volume) and in the air excess coefficient of the resulting anxiliary mixture (0.4 to 0.7), in the wide range of the working mixture air excess and throttling.</div>