Electronic Oil Injection
1989 - 1999 Mercury and Mariner V-6 Carb Models
Installation Instructions

Test the Oil Warning System per the applicable Mercury Service Manual and assure normal engine compression before beginning installation. Replace all defective and suspect parts, with original Mercury parts.  EOI requires resistor spark plugs such as NGK BUZ8H.

  Remove oil pump  
1.

Disconnect the 12V starting battery.

 
2.

Remove the oil lines and drain the engine oil reservoir tank.

 
3.

Remove the link rod from the oil pump and carburetor linkage.

 
4. Remove the oil pump, bearing assembly and driven gear from the crankcase.  
5. Clean and check that the oil pump rotates freely in a counter-clockwise direction.  
6. Clean and check that the magnet plug is recessed, that the bearing is not damaged, and that the outside diameter of the bearing is under .626 inch to avoid excess friction.  
 
 

Bearing Assembly

 

Driven Gear

 
7. Apply Loctite to the mounting screws and install the crankcase plug supplied.  
  Remove rotation sensor and oil warning module  
1.

Remove the rotation sensor from the engine.

 

2.

Remove the oil warning module if mounted on the left side of the block.

 
  Install bearing assembly, oil pump and rotation sensor  

1.

Replace the o-ring on the bottom of the oil pump with the o-ring supplied.

2.

Install bearing, oil pump, and rotation sensor to the coupler with original hardware

 

 

Crankcase plug installation

Oil pump and rotation sensor
installed on coupler
 
  Assemble EOI mounting plate to the engine  

1.

Apply Loctite and install (3) studs into the crankcase with the short stud in the bottom boss.
Tighten the 3/8 long hex spacers securely against the engine block.

2.

Assemble and hold the EOI mounting plate on the studs. Advance the throttle and check for spark advance lever clearance behind the mounting plate. Correct as necessary.

 


(3) bosses on side of crankcase


Check for clearance behind plate

3. Secure the mounting plate with (2) 3/8 inch hex spacers on the top studs and one hex nut on the bottom stud.  
4. Invert and secure the oil warning module on the studs with (2) hex nuts and washers and the 1-1/4 inch screw, nylon spacer, washer and hex nut at the top of the mounting plate.  
  Assemble Carburetor Linkage  

1.

For Style #1, removed the nut from the throttle shaft and install the link pointing up and to the left. Replace the nut and bend the lock tab over.

2.

For Style #2, remove the throttle lever. Install the link under the lever pointing down and to the left.
Re-install the throttle lever and secure it with the screw.

 
 
  Style #1 for carburetor with threaded shaft. Style #2 for carburetor with smooth shaft.  

3.

Remove the rod end from the original link rod and assemble it to the new link rod

4.

Connect and adjust the link rod to assure that the 1st mark on the pump arm is in alignment with the mark on the oil pump with the throttle at the idle position.

5.

Assure free movement of the oil pump link rod as the throttle is advanced. Note that the oil pump lever needs only to reach half way between the 2nd and 3rd mark to assure full oil delivery at wide open throttle.

6.

Reroute and secure the fuel lines, and check for free operation of the oil pump link rod.

 
 
  Connect wiring  

1.

Route the rotation sensor wires behind the EOI electric motor.

2.

Reconnect the white rotation sensor wire to the oil warning module wire.

3.

Connect the blue/white rotation sensor, and the blue/white oil warning module wires to the blue EOI Y adapter wire.

4.

Connect the black rotation sensor wire, the black EOI controller wire, the black oil warning module wire, and the long black ground wire to the right side EOI mounting plate stud and secure all with the hex nut.

5.

Connect the other end of the long black ground wire to the voltage regulator mounting plate on the back of the engine.

6.

Disconnect the grey tachometer wire from the voltage regulator. Connect the grey EOI wire to the voltage regulator. Reconnect the grey tachometer wire to the grey EOI Y adapter.

 

7.

Secure all wiring with the cable ties supplied but do not tie the gray wire to the red, black or blue wires to avoid electrical noise.

 
 
  Install oil lines  

1.

Check that the 2 psi check valve opens between 1.5 and 2 psi. Replace if necessary.

2

Trim and install the new oil lines and clamps. Reposition the oil pump fittings as needed to assure clearance with the oil pump link rod and throttle linkage.

3.

Refill the oil reservoir and check for leaks.

  System test and start-up  

1.

Connect the red wire to the starter solenoid and reconnect the battery.

 

2.

Turn the ignition key to on and check for audible oil warning module signal. Do not deliver to customer without an audible oil warning module signal.

 

3.

Start engine on 50:1 pre-mix fuel and oil and cooling water. Assure that the oil warning horn is not sounding.
See the troubleshooting section if the horn is still sounding.

 

4.

Disconnect the 3/16” oil pump output line to bleed air from the pump and assure oil flow.  

5.

The pump delivers 1 drop of oil every 2-3 seconds at idle rpm. Reconnect the oil line.  

6.

With the engine running, disconnect the blue-white rotation sensor wire and assure that the oil warning horn sounds. Reconnect the wire to stop the warning horn from sounding. Replace the oil warning module if the horn does not sound.  

7.

Spray electric motor and pump with Quicksilver Corrosion Guard in salt water areas.

 

8.

Cut away the inner air duct on early model bucket cowls to clear the motor and pump.

 

9.

Deliver to customer and explain Operation and Maintenance Instructions.

 
 

Troubleshooting

 


The controller is not be getting a good tachometer signal if the warning horn does not shut off after the outboard is started.

1.

Check for correct and secure wire connections.

2.

Replace the voltage regulator if the tachometer does not work or connect the grey wire to the 2 nd voltage regulator if the engine is so equipped.

3.

Assure that all 6 spark plugs are NGK BUZ8H.

The controller is not getting a good rotation sensor signal if the warning horn comes on and stays on 10-15 seconds after the outboard is started.

1.

Check for correct and secure rotation sensor wire connections.

2.

Check that the rotating magnet has been installed to drive the oil pump.

3.

Replace the rotation sensor.


The warning system may be malfunctioning if the warning horn does not shut off after the outboard is started
.
1.

Remove the two oil pump mounting screws and lift the pump off of the coupler

 
2. Run the engine at idle on premix fuel and cooling water and watch the motion of the plastic bearing.  
 
  • If the bearing is turning slowly for at least 30 seconds, the EOI system is OK.
  • If the bearing does not turn the controller is not getting a good tachometer signal.
  • If the bearing runs fast for 10-15 seconds and then stops the controller is not getting a good rotation sensor signal.
  • See instructions above.
3. Disconnect the float switch wire on the engine oil reservoir cap.
If the warning horn stops fill the tank with oil or replace the float switch.
 
4. Remove the green wire from the #4 ignition coil and connect it to the #2 or #6 coil.
If the warning horn stops, replace the #4 coil.
 

Note: Do not connect the black and red motor wires on the controller to 12V battery voltage.
Do not make unauthorized changes. Call Marine Solutions for advice.