If your Kubota ZG23 zero-turn mower is pulling to the left, it may indicate an issue with the tire pressure, uneven tire wear, or a misalignment in the mower's deck. Check the tire pressures to ensure they match the manufacturer's specifications and inspect the tires for any signs of damage or uneven wear. Additionally, verify that the mower deck is level and properly adjusted. If the problem persists, it may be worth consulting the owner's manual or a professional for further diagnosis.
look for a 11/16 bolt towards the bottom of the engine, it's on the same side as the oil cap and oil filter