To access the carb filter on the 4600, remove the air cleaner assembly. You'll see (or should see) a clear/white piece of tube sticking up about 1/2" on the tank side of the carb. Pull that up and out of the carb and you should see that it's a filter about 2 1/2 " long. If you see any particles in the screen part you can try to blow it out with compressed air. It's best just to replace it. I've used carburetor cleaner spray to clean them.
On the 4600 V2 and V3 there is no idle screw. There should be a spring holding the throttle barrel about halfway closed at idle. (Take off the air cleaner assembly. Look down the throat of the carb and move the lever to see the opening and closing of the barrel.) The spring goes from the lever to the casting for the cable. You may have to adjust the position that the throttle cable is locked up at on the pulley. Roll the throttle handle forward and adjust the cable on the pulley until you have the correct idle, 1500 if you're using a tach, by ear/feel otherwise.