1989 Johnson Evinrude "CE" 9.9 thru 30 Service Manual, P/N 507754, Page 88Get this manual
Intake Manifold Servicing, 9.915 Removal 1Remove the powerhead as described in Section 4
IT] Loosen and remove six intake manifold screws3 Remove intake manifold, leaf plate and two gasketsDiscard gasketsInspection
] 1Inspect the leaf plate assemblies for damage:
The leaf valves and plate must not be distorted The leaf valve tips must not be cracked or chipped The leaf stops must not be 'distorted or loose The check valve disk must be intact and free to move inside the valve The check valve screen must be clean Use machinist's straightedge to check the flatness of the leaf plateThe gasket surfaces must be flat .003 in( 0,08 mm)