780/30 Series Drive Clutch: The 780/30 series primary drive clutch is designed with a 1-inch (25.4mm) bore and a 1/4 inch / 3/4 inch keyway, compatible with most motors, including Briggs Stratton Pioneer, Kohler Command, Robin, Honda, Salsbury, CVTech, and CVTech Powerbloc IBC, and most 4-stroke engine crankshaft sizes mentioned. Replacement part number: 302405A and 302405. Dynamic Balance Performance: Manufactured with strict quality control standards, the drive clutch axle undergoes dynamic balance precision processing. Reducing imbalance caused by parts wear, ensuring firm engagement, efficient operation, and minimizing the potential for abnormal sounds and vibrations. Authentic Replacement Parts: Tailored to match original part specifications, this primary drive clutch assembly serve as the perfect replacements for old or worn components. Offering easy two-step assembly without the need for drive pulley or clutch adjustments. Note: Professional installation is recommended, and attention to the engine's bolt requirements (American or metric) to ensure a secure fit. Durable Alloy Construction: Crafted from iron and aluminum alloy, the primary driving clutch replacement boasts a sturdy build with excellent heat dissipation features. The black surface treatment enhances rust resistance against elements such as oil and rain, prolonging the service life under various environmental conditions. Efficiency and Smooth Operation: If your kart exhibits issues like abnormal noise, vibrations, or steering difficulties, inspecting and replacing the drive clutch can lead to marked improvements. This upgrade ensures your vehicle operates efficiently, navigates bumpy roads with ease, and maintains quick and smooth transitions between engagement and separation states. Package Content 1 x Primary Drive Clutch 1 x Manual （1 x Go-kart Torque Converter Kit 1 x Belt 1 x Manual)for 30 series option