The adjuster sticking through the gear cover (front side) is designed to allow for fine adjustment of the governor via changing the length/tension on the speeder spring. Increasing tension on that spring should speed up the unit by pulling harder against the governor weights and springs and thereby further opening the fuel rack and pumps. If you get no response from turning that screw either way, then the rack might be sticky. Does the unit start easily and rev to the same speed each time? Does it shut down normally with the control on the side? You can remove the side fuel pump cover to observe rack movement and look at connections between the various parts inside. Does the pump rack operate smoothly along the full length of its travel? With engine shut down, put in a finger or screwdriver/probe and push it back and forth. Are all of the parts connected? Take a look and compare with the Instructions Book drawings/images.
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