What's this part?

[dgbull3]

While the boat is winterized, I started going through and cleaning. I found this pin under the engine and am not sure where it's from. Anyone know? Looks to be some sort of locking pin because it has a notch and spring.

25232

[sandm]

muffler bearing?

[zabooda]

Plunger for a water valve solenoid?

[Crane man]

Spark plug heat shield. Spring holds it in the head and plug wire goes inside it.

[Whitey]

The part is a plunger for the solenoid in the sprinkler valve.