Marine propulsion device including ignition interruption means to assist

Abstract

Disclosed herein is a marine propulsion device and apparatus and methods for assisting transmission shifting thereof. The marine propulsion device includes an internal combustion engine and a reversing transmission having a pair of bevel gears and a clutch dog movable between a neutral position out of engagement with the bevel gears and forward and reverse drive positions in full engagement with one of the bevel gears. The marine propulsion device also includes a shift assistance arrangement included in a shift mechanism for axially moving the clutch dog between the neutral and drive positions, and which includes a load sensing lost motion shift lever arrangement having a first switch which is actuated when the resistance to axially moving the clutch dog into a drive position exceeds an upper limit. The shift assistance arrangement also includes an ignition interruption circuit responsive to actuation of the first switch for selectively interrupting the ignition of the internal combustion engine to reduce the engine torque transmitted to the bevel gears to effect relative angular displacement of the clutch dog and the bevel gears to thereby assist the shift mechanism in moving the clutch dog into and out of a drive position. The ignition interruption circuit includes a control circuit having a first timer for providing a plurality of successive timed cycles, each cycle including an ignition-kill interval and an ignition-on interval, and also having a second timer for establishing an overall cycle during which the first timer is operative, subject to the first switch.