CYL GP- 3642422 - Caterpillar

(01Z) Marine EnginesIn some applications (particularly high performance pleasure craft) prolonged low speed operation, such as idling or trolling, can result in white smoke from the exhaust. The white smoke is generally accepted at start-up, but not during normal operation. The prolonged low speed operation can allow the engine to "over-cool" and result in white exhaust smoke.
In the above applications, the standard 9N5121 Water Temperature Regulator can be replaced with 7C3472 Water Temperature Regulator. The 7C3472 Regulator has a 190°F operating temperature and a "low leak" feature. This change will help maintain the correct engine operating temperature, even when operating at low load in low ambient water temperature.
If a 7C3472 Water Temperature Regulator is installed, a 361865 Cap Assembly (14 psi, expansion tank cap) and the use of 50/50 water/glycol coolant mix is recommended.