Our rebuild kit for Sea Doo 4TEC Thermostats will allow you to remove the old thermostat from the housing and replace it with a new one. The SBT Thermostat kit for Sea Doo 4TEC engines can extend the life of the engine by maintaining the proper engine temperature and allows it to produce the horsepower it is capable of. A properly functioning thermostat is a must have item on 4-Tec watercraft and 4-Tec powered jet boats that are operated in warm water climates.