What are these for in the throttle bodies.

Are they for balancing idle?

 

Look like jets but haven’t got a clue really

 

Idle air jets. The idle air control valve is at the bottom of the picture.
The manual lists no adjustments, it's all factory set. Don't undo any of the painted screws.

 

Thanks, I've undone all the painted screws as I'm fitting them to a Honda B16A2 ( keeping it Honda ). There are no holes through them, so not like jets. I think there are a means of balancing the idle across the 4 cylinders.