1997 Johnsoon Evinrude "EU" 50 thru 70 3-Cylinder Service Manual, P/N 507266, Page 94Get this manual
Inspection
1Inspect the leaf plate assemblies for damage: The gasket surface must be flat 0.003 in(0,08 mm) The leaf plates must not be distorted
The leaf tips must not be cracked or chipped
The leaf plate stops must not be loose or distorted
2Inspect the intake manifold
All gasket surfaces must be smooth and free of nicksUse 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
INote All
intake manifold components must be perfectly clean before assemblyDo not use strong carburetor cleaner or hot soaking tank9479
Assembly
rnleafPlace leaf valvesleaf leaf plateIf new valves do not seat on 1on the plate, turn the valves overINotel Used leaf valves must not be turned over for reuseLeaf valve may break when returned to service causing serious powerhead damage