In the stratified charge engine with an auxiliary chamber, the time required for combustion in the main chamber is considered to depend upon the characteristics of the turbulent jet-flame propagating in it. This study has been conducted to explore the controllability of the time required for combustion by changing the characteristics of the turbulent jet-flame. Experiments were performed by using a constant volume combustion chamber which was divided into a primary and a secondary chamber by an orifice plate. The characteristics of the turbulent jet-flame were changed by changing fuel, mixture strength and hole size of the orifice plate.The experimental results indicate that the time τ required for combustion in the secondary chamber mainly depends upon the jet-flame velocity VF (propagation velocity of the leading front of the jet-flame) and the mixture strength Φ. It is shown that a unique relation exists between VF and (τ SL)−1, were SL is the laminar burning velocity of the mixture, except for rich mixtures of propane-air and n-butane-air.