The invention provides a power transmitting system for a small boat, such as a water jet propulsion craft, and more particularly, an improved arrangement for connecting an engine output shaft to a propulsion unit input shaft. Also provided is an arrangement for balancing an engine within the craft against undesirable operational forces tending to render the craft unstable. The connecting assembly includes a coupling arrangement utilizing elastomeric vibration dampening members. One of the dampening members possesses a high degree of elasticity, while another of the dampening members possesses a low degree of elasticity. A durable, yet efficient vibration dampening coupling arrangement, which is additionally able to act as a universal joint, is thereby achieved. The engine balancing arrangement includes a flywheel which rotates in response to the crankshaft assembly of the engine. The flywheel is weighted, and rotates in a direction opposite to that of the crankshaft assembly, so that a rotational momentum is achieved by the flywheel to offset undesirable rotational forces created by the crankshaft assembly