Worn throttle shaft bores are a major contributor to unstable idle due to un-metered air entering carburetor leaning out the idle air/fuel mixture. Eliminates vacuum leaks and restore smooth operation with our quality USA made throttle shaft bushing installation kit. The key to our kit is the specially machined piloted drill bit. The pilot allows proper alignment with simple hand tools. These kits are designed for the "DIY'er" and comes with complete easy to follow detailed instructions. We use the same kit ourselves, best kit on the market.