[Cameron Davis]

I'm trying to get my snowblower working (Poulan Pro PR100) by first cleaning the carburetor. On top of the carb there is a black plastic screw (see pictures). It screws into the metal housing but there is nothing attached to it. What does it do? It it supposed to be adjusted to partially obstruct the opening in the red part directly below? If so, how do I determine how to adjust? There is a small gap between the screw and the red part, so I don't see how moving the screw makes any difference. Thanks.

 

[CodeMatters]

Not sure....does the blk plastic screw protrude out the other side of the
metal it screws into? If so it looks like it could be a min throttle stop.

 

[SeniorSitizen]

According to the manual is the red button the primer?

 

[CodeMatters]

Idle stop screw. See 6:30 of video.