SEASTAR FRONT MOUNT YAMAHA 4-STROKE CYLINDER. Features balanced, even number of steering wheel turns from midship to hard over. HC5345 fits most big new outboard engines except power assist models. Suitable for autopilot interface. Subject to splashwell/bracket depth clearance. Inside diameter is 1.282. Stroke is 10". Volume is 8-1/2 cubic inches. All Seastar outboard cylinders now are rated fro 350 HP engines.