housing and are exhausted below the waterline through an outlet in the propeller hub 36 this arrangement is well known in the prior art and is generally depicted in fig3 which shows a path 38 for the flow of exhaust gas from an exhaust port of the powerhead 8 to the hollow propeller hub 36 the components of a known exhaust housing assembly 26 are shown in the exploded view of fig4 the assembly comprises an outer exhaust housing 40 which is attached to the swivel bracket item 4 in fig1 and 2 via a pair of lower rubber mounts 42 only one of which is shown in fig4 the outer exhaust housing 40 supports the powerhead via an exhaust housing adapter 44 on which the powerhead sits the steering arm assembly item 6 in fig1 is coupled to an upper rubber mount assembly 46 which is installed within a recess in the exhaust housing adapter 44 the exhaust housing assembly 26 further comprises an inner exhaust housing which is supported inside the outer exhaust housing the inner exhaust housing has an inlet at the top which is in flow communication with the exhaust port of the powerhead and an outlet at the bottom which is in flow communication with the hollow propeller hub the inner exhaust housing comprises an upper inner exhaust housing 48 and a lower inner exhaust housing 50 the outlet at the.