Usage:
3516 (3RC),
3512 (4KC),
G399 (49C),
G398A (73B) Spark-Ignited Engines
Description of Change: A new spark plug is used in the ignition groups used on the above engines. The new spark plug has a "J" gap and a precious metal center electrode. It replaces the former surface gap spark plug. The new spark plug can be regapped and will provide increased service life. A replaceable gasket is available for the new spark plug.
Adaptable To: The new 9Y2602 Spark Plug is a direct replacement for the former 7W2257 Spark Plug in the ignition groups shown in the chart. The former spark plug is canceled. The 9Y6792 Gasket is available for use with the new spark plug. A new gasket should be installed each time the spark plug is installed.
The new spark plug is longer and requires a deeper spark plug socket. The new 4C4601 Spark Plug Socket is available to use when removing or installing the new 9Y2602 Spark Plug.
