1988 Johnson Evinrude "CC" 9.9 thru 30 Service Manual, P/N 507660, Page 176Get this manual
30Install the cylinder head using new gasketInstall dry, do not use sealerTighten the cylinder head screws in stages to the final torque of 216-240 inIbs(24-27 Nm), following the sequence shownInstall the thermostat the cylinder head
springand isolator
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Install thermostat cover and O-ring Torque screws to 60-84 inIbs(7 -9 Nm)
33Apply OMC Gasket Sealing Compound to both sides of two new exhaust cover gasketsInstall the inner and outer exhaust coversTighten the screws to torque of 95-130 inIbs(11-14 Nm), starting with the center screws
IS21 IS31
34If the overboard water indicator fitting has been removed from the exhaust cover, apply OMC Gel-Seal II to the fitting threads before installing 35Install the bypass cover using new gasketInstall and tighten the screws to torque of 60-84 inIbs(7-9 Nm)starting with the center screws