Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 118Get this manual
48Rem ove nuts from aft bottom side of powerhead 50Rem ove bolts from oil pump and remove oil pump assembly from block
aNuts (2 Each)
49Lay powerhead on exhaust chest side and remove nuts from bottom of ex hau st exten sion plate Remove exhaust extension plate