Some embodiments are directed to a transmission that includes an input shaft connected to a crankshaft, an output shaft contained within a transmission housing, an input gear contained within the transmission housing and connected to the input shaft, and an output gear contained within the transmission housing and connected to the output shaft and engaging the input gear. A directional gear assembly is contained within the transmission housing at a location between the output shaft and the drive shaft. The directional gear assembly includes a first configuration in which the output shaft drives the drive shaft in a first rotational direction, a second configuration in which the output shaft drives the drive shaft in a second rotational direction that is opposite to the first rotational direction, and a third configuration in which the drive shaft is disconnected from the output shaft.