Gen 1 to Gen 2 cooling system conversion kit for Stark VARG. Upgrades the cooling circuit by returning air bubbles directly from the pump back to the top of the radiator, significantly improving system bleeding and reducing the risk of air lock. Recommended upgrade for all Gen 1 VARG MX 1.0 bikes. The VARG MX 1.2, EX and SM are already equipped with this Gen 2 cooling system.