2001 Mercury Mariner 50-60HP Factory Service Manual, Page 213Get this manual

2001 Mercury Mariner 50-60HP Factory Service Manual, Page 213

CYLINDER HEAD
NO1 AND NO2 INTAKE VALVES NO1 AND NO3 EXHAUST VALVES 1Turn the driven gear and align the "n" mark on the gear with the cylinder head mark "n"2Adjust the valve clearance for No1 and No2 intake valves and No1 and No3 exhaust valves