What is under this plate on my inlet manifold??

[SOB59]

While taking off my air cleaner for the first time I noticed this round disc loose. What does this do & should it be loose?? Also, what is under this plate the disc seats on?? Be easy on me I'm still learning... Hah Hah!!
Oh and the motor is a 361.......

 

[clazar]

Yes, it's suppopsed to be loose. Under the plate is your choke spring that heats up when the engine is on. It opens & closes the choke on the carb.

 

[Builderguy]

Kinda like this one.

 

[SOB59]

Cheers Clazar that clears that up........

 

[Runcharger]

That helps keep the heat in the choke well and dirt out.