2003-2005 Kawasaki Ultra-150 Jet Ski Factory Service Manual., Page 41Get this manual
PERIODIC MAINTENANCE 2-13 Periodic Maintenance Procedure
To prevent clogging, the bilge system should be flushed out according to the Periodic Maintenance Chart, or whenever you suspect it is blockedDisconnect both bilge hoses at the plastic breather fitting [A]
ne e( he Congarcdtetn ehobsilese, ftiultrenr thosws tefrroom, tandhfuullsboitttomt) foor the he ou about minuteDuring this procedure, water will flow into the engine compartmentDo not allow large amount of water to accumulate in the engine compartmentConnect the other hoses (from the hull bulkhead) to the garden hose, turn the water on, and flush it out for several minutes