Engine Assembly of Mercury/Mariner V6 Powerheads

• Check latest Mercury Service Bulletins.
• Install .0002" larger jets in carburetors.
• Max timing should be retarded 2 degrees.
• Remove advance box if installed.
• Remove idle stabilizer if installed.
• Rebuild carburetors and fuel pump.
• Retorque heads to 40 ft/lbs.
• After 1 hour running, allow engine to cool and recheck torque. Retorque to factory specs if necessary.
• Crowley Marine suggests removing oil injection system.
• If oil injection is used, replace 2 PSI oil valve and check oil pump bushing and seal.
• Clean and refill oil tanks with TCW-3 oil.
• Verify oil comsumption during break-in by marking the oil tank level.
• Check overheat alarm system and horn.
• On 2.5 EFI engines, fuel pressure should be 39 lbs. minimum.
• 2.5 EFI engines may have as many as 7 fuel filters, remove the cone shaped filter inline below the electric pump.
• Use newest style head gaskets and replace every year to prevent failure.
• Replace water pump impeller and gasket every year to prevent head gasket failure.
• Use 92-94 octane premium fuel.

Carefully following these instructions will aid in the proper assembly & break-in of your Mercury V6 engine