Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 125Get this manual
Crankshaft 1Inspect crankshaft to drive shaft splines for wear(Replace crankshaft, if necessary
2Check crankshaft for straightness(Replace as necessary
3Inspect crankshaft oil seal surfacesSeal ing surfaces must not be groovedpitted or sc ratched(Replace as necessa ry
4Check all rankshaft bearing surfaces for rust, water marks, chatter marksuneven wear andl or ove rheating (Refer toConnecting Rods",)
6Thoroughl clean (with solvent) and dry rankshaft and crankshaft ball bearingRecheck su rfaces of crankshaftReplace rankshaftif surfaces cannot be properly "cleaned up"If crankshaft will be reused, lubricate surfaces of crankshaft with lig ht oi to prevent ru stDO NOT lubricate crankshaft ball bearing at th is time
Reed Block Assembly
IMPORTANT: DO NOT remove reeds from reed blocks, unle replacement Is necessaryDO NOT turn used reeds over for re useReplace reeds In sets only1Thoroughy clean gasket surfaces of reed blocks and reed block housingCheck for deep grooves, cracks and istortion that could cau se leakageReplace parts as necessary2Check for wear (indentations) on face of each reed blockReplace block(s) if reeds have made indentations3Check for ch ipped and broken reeds4Allowable reed openi ng is .020" (.51 mm) or less Replace reeds if either reed is standing open more than .020" (.51 mm )