2003 Johnson ST 55 HP WRL 2 Stroke Commercial Service Manual, PN 5005483, Page 117Get this manual
FUEL SYSTEM
INTAKE MANIFOLD
Inspect the intake manifold: All gasket surfaces must be smooth and free of nicks Use machinist's straightedge to check for flatness in all directionsThe mounting surface must be flat, 0.004 in (0.10 mm) Balance passage must be free from any restrictions
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 burrs
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 adhesive