Mercury Mariner 4, 5 102CC Sail 1990 Outboard Service Shop Manual, Page 72Get this manual
10Ch ec each iston ring for sp ring tension thru exhaust port by pressing with screwdriverIf no spring tension exists (ring fai ls to return to posil ion)it is likely Ihat the piston ring was broken du ring assem bly, and musl be replaced 13Apply Loctite Grade "A" (271) to thread of two screws (a) and secure reed stop (b) and reed valve (c) Torque screws to lbin (1 Nm)
11 Rotatecrankshaft several times to assure free operation 12Align locating corners reed valve and reed stop together and assemble as shown