| 摘要 |
An inboard gasoline marine engine for small water craft comprises a two cylinder horizontally opposed four stroke engine. The engine includes a massive crank shaft rotationally mounted in the crank case of the engine. A small flywheel is connected to one end of the crank shaft. The flywheel additionally drives the propulsion system used along with the engine. The fly wheel is typically disposed at the back of the engine, although positioning the flywheel in the front position would also be possible. Opposite the flywheel on the front of the engine is a main belt for operation of an alternator, and a cover for a timing belt or chain. Two cam shafts are driven by the crank shaft through the timing belt or chain. A cylinder block or jug is located on each end of the crank case. A large bore cylinder (4¼ in.) is disposed in each cylinder jug. Reciprocating in each cylinder is a large diameter piston that has a long stroke (5 in.). Each piston is connected to the crank shaft through a long connecting rod (10 in.). A cylinder head and valve cover are mounted at each end of the engine. Water jackets, that are designed for a marine engine surround the cylinder blocks. A fuel delivery system is used to provide fuel to each cylinder. Specifically, a carburetor is located adjacent to each cylinder head. The engine is capable of operating at very low RPM's. The engine also produces high torques at low seeds. The engine is of a size that minimizes the space occupied by the engine within the small water craft.
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