Adjust idle to 700-750

adjust set idle mix screws to strongest idle or vacuum while in gear not neutral (carefully)

readjust idle if needed to 700-750

if the idle mix screws are ineffective, or cannot shut down the engine by closing one screw,

then your metering block is boogared up, and idle fuel orifice is clogged.

Address fuel filtering issue and clean metering block passages. idle fuel orifice is not viewable 

- Turn engine off

- Remove spark arrestor (you want to be able look look down into the carb)

- Remove the throttle linkage socket that connects to the ball on the carb linkage (spring loaded)

(The 4160 carb has a primary and a secondary circuit.  The primary circuit is the one with the choke plates.)

- While looking down the carb into the primary venturis, quickly rotate the carb linkage from "idle" to "full throttle"

- You should se a nice, steady stream of gasoline squirt from 2 nozzles into the primary venturis

The squirt should be instantaneous with the throttle opening.  If the squirt is not instant with the throttle or if the stream is weak, you may have an accelerator pump that needs some TLC.

JQ