This spacer for 3-bolt Linkert carburetor moves the carburetor further out to create more distance from the hot cylinders. The proximity to the hot cylinders could lead to vapor lock of the fuel in the carburetor or fuel lines. Poor throttle response and difficult restarting are usually the result. In contrast to the Big Twin Sidevalve models, where the intake manifold was lenghtened in 1939, the 45"/750cc models used this adapter from 1941 until the manifold was lenghtened in 1943. On WLD models 1941-1942 the manifold remained short.