Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 198Get this manual
Priming the Oil Injection Pump (Continued) 1998 MODELS
Purging Air From the Engine Oil Reservoir
1Loosen the fill cap on the engine oil tank2Start the engineRun the engine until the all the air has been vented out of the tank and oil starts to flow out of the tankRe-tighten fill cap
Before starting engine for the first time, or for an engine that ran out of oil, or was drained of oil,
prime the oil injection pumpPriming will remove any air that may be in the pump, oil supply hose, or internal passages
aFill Cap
aOil Injection PumpOil Supply Hose