2004 SR Johnson 2-stroke 40, 50HP Service Manual, Page 169Get this manual
FUEL SYSTEM INTAKE MANIFOLD IMPORTANT: Used leaf valves must not be turned over for reuseLeaf valve may break when returned to service, causing serious powerhead damageIf any leaf valves are standing open, apply light pressure using pencil eraserIf leaf valve closes with light pressure, valve is acceptableIf not, inspect leaf plate for high spots or burrsLeaf plate may be sanded lightly to remove burrsUse sharp pencil to mark the edges of leaf valves IMPORTANT: Do not polish leaf platesIf plate
is too smooth, the leaf valves may stick closed after off-season storageApply Locquic Primer to mounting screws and allow to air dryApply Screw Lock to mounting screwsWipe off excess adhesiveUse pencil eraser to gently open the leaf valves to check the alignment of the valve over the portValves should be spaced evenly over portIf not, loosen mounting screws and reposition leaf valve