Synchronizers for maintaining the speeds of two or more internal combustion engines in synchronism with each other are well known. Such synchronizers are commonly used in boats having twin propulsion screws driven by twin engines for maintaining the engines at the same operating speed. A mechanical device for synchronizing marine engines is described in the Herbert U.S. Pat. No. 3,258,927 granted July 5, 1966. Electronic synchronizers are described in other prior art patents. In the Beaman et al U.S. Pat. No. 3,986,363 granted Oct. 19, 1976, a synchronizer is described in which a servo is connected to move the sheath of a push-pull cable for throttle adjustment while the throttle lever acts through the wire of the cable for throttle adjustment. A similar arrangement is described in the Stewart U.S. Pat. No. 4,435,961 granted Mar. 13, 1984. In the Kobus U.S. Pat. No. 4,586,341 granted May 6, 1986, the servo motor drives a lead screw and nut which effectively shortens or lengthens the cable wire of a push-pull cable to make throttle adjustments.
There is a need for an improved synchronizer which is self-contained and compact which interfaces with resisting controls.