Conversion kit adaptor for a Keihin carburetor to ensure a perfect fit with the rubber hose that connects the carburetor to the reed valve cage. Especially recommended when changing from a Dellorto to a Keihin PWK 28mm carburetor on a Gas Gas trials bike. KEIHIN CARBURETTOR CONVERSION - BLACK GAS-GAS TXT/PRO/RACING/GP 02-24 Apico Gas Gas dellorto to keihin conversion kit. When fitting a keihin PWK28 carb to a Gas Gas pro, this fixes both the diameter and length problems. Due to the keihin carb being shorter it makes up for the length difference and converts the diameter of the front of the carb to allow it to slide straight into the standard reed block.