Mercury Marine washer 12-879172191 is a genuine OEM washer for selected MerCruiser CMD 4.2 marine diesel engines. The part is identified by Mercury part number 12-879172191 and manufacturer number 879172191.
The washer is documented for the CMD 4.2 EI and ES models 250, 270, 300, and 320. It also fits the CMD 4.2 MI and MS models 200 and 230. Compatibility depends on the engine model and serial number.
For EI 250 and ES 250, the serial number range is 88040600-88050000; for EI 270 and ES 270, it is 88060001-88070000; for EI 300 and ES 300, it is 88050800-88060000; and for EI 320 and ES 320, it is 88070001-88080000. MI 200 and MS 200 are covered in the serial number range 88020200-88030000, while MI 230 and MS 230 are covered from 88030400 to 88040000.
Part number 879172191 replaces the previous OEM number 879172169. Always check the engine's full model designation, serial number, and existing part number before ordering.
Key featuresGenuine Mercury Marine OEM washer
Part number: 12-879172191
Manufacturer number: 879172191
Replaces OEM number 879172169
For selected MerCruiser CMD 4.2 diesel engines
GTIN: 745061841994
Compatibility must be checked against model and serial number
