Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 58Get this manual
TimingSynchronizing Adjusting Firing Order Firing Sequence Spark Plug Spark Plug Gap iming Maximum
4Reposition tim ing pointer (if necessary) so that timing pointer is aligned with.557 mark on flywheelas shownRet ighten pointer attaching screws
1-2-3-4-5-6 600 Consecutive
NGK-8U8H Champion L6VC Not Ad justable 20 BTDC (22 at Cranki ng) ATDC Not Adj ustable
Th rottle Prima ry Pickup Throttle Secondary Pickup Full Th rottle RPM Idle RPM (in Forward Gear)
5000-5500 600-750 (5 ATDC)
Timing Pointer Adjustment
AWARN ING
Engin ould start when turning flywheel to check liming pointer adjustmentRemove all spark plugs from
aTiming PointerAlign with .557 MarkTiming Pointer Attach ing Screws
engine to prevent engine from starting 1Remove all spark plugs and install Dial Ind icator