Mercury Optimax 115 Service Manual page 201

Table of Contents
Oil System Operation . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Pump Output . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Hose Check Valve Installation on 1998 Model
135/150 DFI Outboards SN 0G886266 and
Below . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Injection Hose Installation
Oil Pump Removal and Installation
Engine Oil Reservoir Removal and Installation 3C-11
Oil System Operation
Oil in this engine is not mixed with the fuel before entering the combustion chamber. Oil
is stored inside the remote oil tank in the boat. Crankcase pressure forces oil from the
remote oil tank into the engine oil reservoir. The engine oil reservoir feeds oil to the oil
pump. The oil pump is ECM driven and controls oil distribution to the crankcase and air
compressor. The oil pump has seven oil discharge ports. Six of the oil discharge ports in-
ject oil into the crankcase through hoses, one hose for each cylinder. The last oil discharge
port discharges oil into the air compressor for lubrication. Unused oil from the air compres-
sor returns to the plenum and is ingested through the crankcase.
The ECM is programmed to automatically increase the oil supply to the engine during the
initial engine break-in period. The oil ratio is doubled during the first 120 minutes of opera-
tion whenever engine speed exceeds 2500 RPM; below 2500 RPM the oil pump provides
oil at the normal ratio. After the engine break-in period, the oil ratio will return to normal
- 300 - 400:1 at idle to 60:1 at WOT.
NOTE: On some light boat applications after the break-in is completed and the engine is
being run at cruising speed - between 4000 and 5000 RPM - the fuel to oil ratio may be
as high as 28:1. This results from a reduced throttle opening with a corresponding reduc-
tion in fuel consumption.
Oil Pump Output
Using the DDT to activate auto prime, the oil pump should discharge 110 ml (cc)
(cc) during the auto prime time period.
To check the oil pump output:
Verify the onboard oil reservoir is full.
Release any pressure (loosen cap) from the remote oil tank in the boat.
With engine not running, use the DDT to activate the auto prime.
Using a ml or cc graduated container, record the amount of oil needed to refill the on-
board oil reservoir.
Retighten cap on the remote oil tank in the boat.
90-855347R1 JANUARY 1999
FUEL SYSTEM
Section 3C - Oil Injection
3C-1
3C-1
3C-2
3C-3
. . . . . . . . . . . . . . . 3C-9
. . . . . . . . 3C-10 Oil System Troubleshooting
Priming the Oil Pump . . . . . . . . . . . . . . . . . . . .
Priming Procedure - Method 1
Remote Oil Hose Connections
Filling the Oil Tanks . . . . . . . . . . . . . . . . . . . . . .
Purging Air From the Engine Oil Reservoir
and Remote Oil Hose . . . . . . . . . . . . . . . . . . . .
Oil Warning Systems . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . .
Low Oil Warning System is Activated
OIL INJECTION
3C-12
. . . . . . . . . . . . 3C-13
. . . . . . . . . . . . 3C-14
3C-14 3
3C-15 C
3C-15
3C-16
. . . . . . 3C-16
8 ml
Page 3C-1