an engine adapted for installation within a sailplane , comprising : a charger assembly a charger cylinder comprising : a inlet port for receiving fuel mixture ; and an outlet port ; and a charger piston reciprocally disposed within the charger cylinder such that , the charger piston is movable between top and bottom positions , the charger cylinder to receive the fuel mixture there within when the charger piston is at the top position , the fuel mixture to egress through the outlet port as the charger piston slides to the bottom position .