Mercury Mariner 25HP 4-Stroke Outboard Service Manual 1997, Page 148Get this manual
Specifications CYLINDER BLOCK STROKE Ty pe Displacement Number of Cylinders Length
4 Stroke CycleOver Head Camshaft 30.4 cu in(498cc) 2.953 in(75 mm)
2.5591 in(65 mm) 2.5689 in(65.25 mm) 2.5787 in(65.5 mm) 0.003 in(0.08 mm) Cast Iron
Diameter
CYLINDER BORE
Standard Oversize-0.010 in(0.25 mm) Oversize-0.020 in(0.50 mm) TaperOut of Round Maximum Bore Type
Pislon Type
Aluminum
2.55702.5578 in(64.95064.965 mm) 2.56692.5675 in(65.265.215 mm) 2.57682.5774 in(65.45065.465 mm) 0.0014.0026 in(0.0350.065 mm)
0.0al Skirt
PISTON Slandard Oversize-0.010 in(0.25mm) Oversize-0.020 in(0.50mm)
Piston to Cyli nder Clearance
PISTON CLEARANCE