Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 61Get this manual
9With engine in neutralmove throttle lever to place maximum spark advance screw against stopCrank engine with starter motor and adjust maximum spark advance screw to align 22 mark on fl ywheel with liming pointerDue to the spark advance characteristics of this ignition system, this adjustment will result in spark advance of 20 BTDC at 5500 RPM a e
Full Throttle Slop Screw Push Throttle linkage Downward .010" .015' (0.2Smm O.3Bmm) Clearance Roller Throttle Cam
CarburetorOil Pump Synchronization
1Whi le hold ing throttle arm at idle positionadjust length of link rod (a) so that stamped mark (b) of oil pump body aligns with first (shortest) stamp mark (c) of oil pump lever