Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 248Get this manual

POWERHEAD
Cleaning and Inspection
Cylinder Block and Crankcase Cover
IMPORTANT: Crankcase cover and cylinder block are matched, line-bored assembly and never should be mismatched by using different crankcase cover or cylinder block
CAUTION

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives