Mercury Mariner 8/9.9HP 4-Stroke Factory Service Manual, Page 127Get this manual
Cleaning and Inspection Oil Pump
NOTE: If the oil pump clearances does not fall within specifications, replace the oil pump assembly1Check oil pump components for pitting and scratching2Using feeler gauge, measure the following oil pump clearances: between outer rotor and pump housing (a) between the inner rotor and outer rotor (b) between the outer rotor and pump housing (c)
Rocker Shaft and Rocker Arm
NOTE: Measure and inspect the rocker shaft and rocker arms for excessive wearIf any of the components fall out of specifications, replace1Measure Rocker Shaft