2003 Polaris MSX 140 Personal Watercraft Service Manual, Page 83Get this manual
EngineCooling W120HO- DFI Cooling System Overview Thermostat Pop Off Assembly
If low end performance of the watercraft begins to deteriorate, and the jet pump intake area is free of debris and weeds; or if the overheat alarm sounds, the thermostat pop off assembly should be checked for debris and cleanedAlso inspect the thermostat pop off assembly if the watercraft has been stored for more than 30 days or has been used in salt waterTo do this, use 316 (.5 cm) Allen wrench and flat screwdriverCAUTION: If the thermostat pop off assembly is reassembled incorrectly severe engine damage will result within very short period of operationNOTE: Do not perform this maintenance while the watercraft is in the waterThe thermostat pop off assembly is under tension from an internal springWhen the screws are removed, the assembly will come apart quickly if not held together firmly1Remove screws while holding thermostat pop off assembly firmly togetherCarefully take assembly apartBe careful not to lose any parts2Check thermostat pop off assembly for debris, such as seaweed, and clean it out3Check condition of rubber elementsAlso check thermostat and housing for corrosionReplace any parts that appear in poor condition4Assemble thermostat pop off assembly in correct sequence, and by holding the entire assembly togetherAssemble carefully to ensure proper alignment between all internal parts and be sure the gasket or O-ring is properly positioned5Attach thermostat pop off assembly using screws removed in step one and Loctitet 242 (blue)