1990 Johnson Evinrude "ES" 9.9 thru 30 Service Manual, P/N 507871, Page 94Get this manual
Disassembly Do not disassemble leaf plate assemblies unless leaf plate seats, leaf valves, or leaf stops are damaged or corroded1sl 1Remove one screw and nut per leaf valve and remove the leaf plate assemblies as required2When disassembled, keep the stops and leaf valves separated by assemblyAssembly All intake manifold components must be perfectly clean before assemblyDo not use strong carburetor cleaner or hot soaking tank l!J the leaf plate, switch the leaf valves
f711Place leaf valves on leaf plateIf new valves do not seat on Used leaf valves must not be turned over for reuseLeaf valve may break when returned to service, causing serious powerhead damage12687
2If 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 burrs 19l 3