| 摘要 |
PURPOSE:To accurately control temperature of cooling water, by providing protrusive parts from a crank case and cylinder head, extensibly winding a belt between driving and driven members and providing a thermostat housing chamber in said protrusive part and between tight and loose sides of the belt. CONSTITUTION:A crankshaft 11 and cam shaft 23 are protruded respectively in the upper part of a crank case 10 and the upper part of a cylinder head 19 in an internal-combustion engine 4 of outboard engine, and a driving gear 15 and driven gear 16 are provided respectively in the both protruded end parts, while a toothed belt 29 is wound on the both gears. A housing chamber 41 of a thermostat 46, controlling a cooling water amount to an outflow case 44, is mounted in a position between tight and loose sides of the belt 29 and in a place connected to the uppermost part of a water jacket 40. The thermostat 46 is mounted to the uppermost part of the water jacket 40, where cooling water is at the highest temperature, and temperature of the cooling water is accurately controlled, then operating temperature of the internal-combustion engine can be maintained to an optimum level. |
