Please help identify carb linkage parts

[89-300ce]

I haven't had my carbs off yet and am trying to get a grip on the choke operation. I stole this picture of the web. Can you tell me if I've got something wrong, and what item 4 is?

1 - Bellcrank
2 - Main butterfly shafts
3 - Choke butterfly shafts
4 - ?????

Thanks.

 

[dan filipi]

That's the part of the choke mechanism which bumps the idle speed up.

 

[89-300ce]

Thanks,

Are there any adjustments possible there?

 

[dan filipi]

The tab can be bent to adjust the full choke idle speed.
Normally that's not needed because varying the choke pull will adjust cold idle.