S&S, idle mixture screw, O-ring for Harley-Davidson

- With O -Toric Board (Late Style E/G)
- It adapts only to Super E and G carburetors of late style.
Note: Never tighten the inactive mixture screws too much in carburetors E and G.
It is very easy to damage the idle mixture screw seat at the soft aluminum carburetor housing.
This is very difficult or impossible to repair.
It can cause an irregular idle.
Note: The old style mixing screw (approx. Prior to 2013) (MCS 977815) is not interchangeable with the recent style mixing screw (approx. 2013 onwards) (MCS 940521) with O -ring.
Last style carburetor body can be identified by the text "Made in USA" next to the "Shorty" text.

Units 5