Find the Craftsman Zero Turn lawn mower's flywheel. Open the engine hood and look for the large, circular iron part near the top of the rear of the engine assembly. This visible part of the flywheel is actually the flywheel shroud, which acts as a cover to protect the flywheel. Remove all the bolts from the shroud with a socket wrench and pry it off.
Look for the magneto, which sits on the side of the flywheel beneath where the shroud was. You can quickly identify the magneto by the governor's plastic flap, which lies atop it. The flap is held down by one bolt. Remove it with your socket wrench.
Identify the engine's bowl-shaped carburetor midway along the left side of the engine. An eyelet on the carburetor holds the governor's rod. Remove the rod from this eyelet by pulling it out. This will adjust the governor so that there is no restriction on your Craftsman Zero Turn lawn mower's top speed.