The Professional Standard: James Gasket CV Carburetor Rebuild Kit

For nearly two decades, the Keihin CV (Constant Velocity) carburetor was the heart of the Harley-Davidson lineup. From the final years of the Evolution era to the peak of the Twin Cam and the longevity of the Sportster, the CV40 provided reliable, smooth power. However, over time, the internal seals can become brittle, leading to vacuum leaks, “carb farts,” and inconsistent idling. The James Gasket CV Carburetor Rebuild Kit is the premier choice for riders and mechanics looking to restore factory-fresh performance to their 1988–2006 Harley-Davidson. James Gasket has built a reputation on precision, and this kit (replaces OEM #27006-88) provides the high-quality components necessary to ensure your fuel system is airtight and leak-free.

Engineered for Modern Fuel Challenges

One of the biggest threats to vintage and late-model carburetors is modern pump gasoline. The addition of ethanol to today’s fuel can cause standard rubber gaskets to swell, warp, or dissolve over time. James Gasket addresses this by utilizing premium, ethanol-resistant elastomers in their O-rings and diaphragms. This ensures that once you perform your rebuild, your carburetor stays sealed and functional, even if the bike sits during the winter months. This kit is a comprehensive solution, providing more than just a bowl gasket. It includes every critical O-ring and seal required for a complete bench-top teardown of the CV40, allowing you to clean every passage and replace every point of failure.

Comprehensive Component List and Technical Specs

The James Gasket kit is designed for a direct “bolt-in” restoration of the fuel system. It targets the most common wear points that cause tuning headaches and poor throttle response.

• Float Bowl Gasket: Precision-molded for a perfect, leak-free seal between the bowl and the carb body.
• Accelerator Pump Diaphragm: Restores that snappy, off-idle response that is often lost when the original rubber hardens.
• O-Ring Assortment: Includes seals for the idle mixture screw, drain screw, and the manifold interface.
• Compatibility: Fits all 1988–2006 Sportster (883 and 1200) and Big Twin (Evo and Twin Cam 88) models equipped with a factory CV carburetor.

Installation Tips for Success

To get the best results from your James Gasket Rebuild Kit, we recommend a thorough cleaning of the carburetor body using a dedicated carb cleaner and compressed air. Ensure that all small passages, particularly the idle and intermediate circuits, are free of varnish. When installing the new O-rings, a tiny amount of silicone lubricant can help prevent pinching. Once reassembled, this kit will provide a rock-solid foundation for tuning, helping you achieve a steady idle and smooth acceleration through the entire powerband. Rebuilding your CV40 is one of the most rewarding DIY projects for a Harley owner, and this kit makes it easier than ever.