Engine cylinder head coolant jacket

FIG. 1 illustrates a personal watercraft 10 which includes a marine engine 12 configured in accordance with a preferred embodiment of the present invention. Although the present engine 12 is illustrated in connection with a personal watercraft, the engine 12 can be used with other types of watercraft as well, such as, for example, but without limitation, small jet boats and the like.

Before describing the engine 12, an exemplary personal watercraft 10 will first be described in general details to assist the reader's understanding of the environment of use and the operation of the engine 12. The watercraft 10 includes a hull 14 formed by a lower hull section 16 and an upper deck section 18. The hull sections 16, 18 are formed from a suitable material such as, for example, a molded fiberglass reinforced resin. The lower hull section 16 and the upper deck section 18 are fixed to each other around the peripheral edge 20 in any suitable manner.

A passenger seat 22 is provided proximate to the