Every 300 Hours Of Use Or Three Years; Before Periods Of Storage; Battery Inspection; Flushing The Cooling System - Mercury 15 EFI FourStroke Service Manual

Tube Ref No.
Anti-Seize Compound
81
• Add Quickleen to the fuel tank.
Tube Ref No.
Quickleen Engine & Fuel
System Cleaner
• Check the cowl seals to ensure that the seals are intact and not damaged.
• Check that the idle relief muffler is in place, if equipped.
• Inspect the thermostat for corrosion or a broken spring. Verify the thermostat closes completely at room temperature.
• Check the mounting fasteners that secure the outboard to the boat transom. Tighten the fasteners to the specified torque.
Refer to Section 1D ‑ Installing Outboard on Transom.
• Check the tightness of screws, nuts, and other fasteners.
• Check for loose hose clamps and rubber boots on the air intake assembly.
• Lubricate the driveshaft splines with Extreme Grease.
Tube Ref No.
Extreme Grease

Every 300 Hours of Use or Three Years

• Tiller handle models: Lubricate the throttle cable barrels and the shift cable rod end with 2‑4‑C with PTFE.
Tube Ref No.
2-4-C with PTFE
95
• Verify the throttle and shift cables are properly adjusted.
• Lubricate all lubrication points. Lubricate more frequently when used in saltwater. Refer to Lubrication Points.
• Replace the spark plugs. Refer to Spark Plug Inspection and Replacement.
• Check the remote control cable adjustment, if applicable.
• Inspect the timing belt.
• Lubricate the splines on the upper driveshaft.
• Inspect the wiring and connectors.
• Replace the water pump impeller.
NOTE: Replace the water pump impeller more often, if overheating occurs or reduced water pressure is noted.

Before Periods of Storage

Refer to Storage Preparation.

Battery Inspection

The battery should be inspected at periodic intervals to ensure proper engine starting capability.
IMPORTANT: Read the safety and maintenance instructions which accompany your battery.
1. Turn off the engine before servicing the battery.
2. Ensure the battery is secure against movement.
3. Battery cable terminals should be clean, tight, and correctly installed. Positive to positive and negative to negative.
4. Ensure the battery is equipped with a nonconductive shield to prevent accidental shorting of battery terminals.

Flushing the Cooling System

Rotating propellers can cause serious injury or death. Never operate the boat out of the water with a propeller installed.
Before installing or removing a propeller, place the drive unit in neutral and engage the lanyard stop switch to prevent the
engine from starting. Place a block of wood between the propeller blade and the anti‑ventilation plate.
90-8M0125265 eng NOVEMBER 2017
Description
Description
Description
Description
Throttle cable barrels and the shift cable rod end
!
Where Used
Spark plug threads
Where Used
Fuel tank
Where Used
Driveshaft splines
Where Used
WARNING
© 2018 Mercury Marine
Maintenance
Part No.
92-898101389
Part No.
8M0047931
Part No.
8M0071842
Part No.
92-802859A 1
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