LOL,,, how in the world do you change the idle screw's O-ring in a 40B carb, I have the carb apart and all cleaned, but the new O-ring is not going in for me,,,

I have the correct O-ring "24981837"

thanks !! !!
Jim

The O.S. Max #40B carburetor uses this o-ring on the idle needle:

OSMG7392 22781800 O-RING SMALL #2K/#2SB $2.29

The one you asked about, "24981837" is an o-ring for the high-speed needle.

OK thanks !!

Jim