Chrysler 100, 115 and 140 HP Outboard Motors Service Manual, OB 3439, Page 146Get this manual
9Install exhaust port cover as follows :
AClean gasket surfaces on power head BApply anti-seize to threads of exhaust port cover screws, Special Tool NoT 2987- 1Clnstall in this order: one new gasketex haust port plate, second new gasket, exhaust port cover Figure 61 .EXHAUST PORT COVER
Figure 62Installing Exhaust Port Cover Assembly