Changing The Water-Separating Fuel Filter; Lubrication; Steering System - Mercury 4.3 TKS series Operation & Maintenance Manual

2. Disconnect the PCV valve from the hose and discard the valve.
3. Install a new PCV valve in the valve cover and reconnect the hose.
4. Ensure that the PCV valve is tightly seated in the valve cover.
Changing the Water‑Separating Fuel Filter
Fuel is flammable and explosive. Ensure that the key switch is off and the lanyard is positioned so that the engine cannot
start. Do not smoke or allow sources of spark or open flame in the area while servicing. Keep the work area well ventilated
and avoid prolonged exposure to vapors. Always check for leaks before attempting to start the engine, and wipe up any
spilled fuel immediately.
1. Allow the engine to cool down.
NOTE: Mercury MerCruiser recommends that the engine be shut off for 12 hours prior to filter removal.
2. Close the fuel supply valve, if equipped.
3. Wrap the water‑separating fuel filter with a cloth to help catch any fuel spills or spray.
4. Remove and discard the water‑separating fuel filter and sealing ring from the mounting bracket.
5. Coat the sealing ring on the new filter with engine oil.
Tube Ref. No.
6. Thread the filter onto the bracket and tighten securely by hand. Do not use a filter wrench.
7. Open the fuel supply valve, if equipped.
8. Ensure that the engine compartment is properly ventilated.
9. Supply cooling water to the engine.
10. Start the engine. Check for gasoline leaks around the fuel filter assembly. If leaks exist, stop the engine immediately.
Recheck the filter installation, clean spilled fuel and properly ventilate the engine compartment. If leaks continue, stop the
engine immediately and contact your authorized Mercury MerCruiser dealer.

Lubrication

Steering System

Incorrect cable lubrication can cause hydraulic lock, leading to serious injury or death from loss of boat control. Completely
retract the end of the steering cable before applying lubricant.
NOTE: If the steering cable does not have a grease fitting, the inner wire of the cable cannot be greased.
90-8M0113857 DECEMBER 2015
eng
Description
Synthetic Blend MerCruiser Engine Oil
SAE25W‑40
a
a - Fuel filter base
b - Sealing ring
c - Fuel filter
b
c
6527
WARNING
!
Filter sealing ring
WARNING
!
Section 4 - Maintenance
Where Used
8M0078630
Part No.
Page 43