Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 370Get this manual
bPress crankshaft oul of lower ball bearing as shown INSTALLATION OF NEW DRIVE GEAR Slide oil pump drive gear (flange facing down) onlo crankshaftAlign sial in gear wilh keyway on crankshaftSeal gear against counter weight shoulder
51081 Press Powerhead Stand (9 130591Al) Crankshaft Ball Bearing Universal Puller Plate (91 37241) 52326Flange (Faces Down Towards Ball Bearing) KeywayShoulder
Slide oil pump drive gear off of crankshaft