Mercury 225 EFI, Service Manual

Page: 292 / 719

OIL INJECTION
Page 3C-2 90-884294 OCTOBER 2001
CAUTION
Be careful not to get dirt or other contamination in tanks, hoses or other compo-
nents of the oil injection system during installation.
Operation of the Oil Injection System
The oil injection system delivers oil mixture on engine demand, from 120:1 at idle to 50:1
at wide open throttle.
Oil is stored inside a remote oil tank in the boat. This tank holds enough oil for approxi-
mately 150 gallons of fuel at wide open throttle.
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 engine oil reservoir contains enough oil
for 20–25 minutes of full throttle running after the remote oil tank is empty. The warning
horn will sound if the oil level in the engine oil reservoir is low.
The oil pump is ECM driven and pumps oil to the vapor separator tank where it mixes with
fuel supplied by the engine mounted pulse pump.
The ECM is programmed to automatically increased the oil supply to the engine during
the initial engine break-in period. The oil ratio during the first 120 minutes is 100:1 @ idle
and 40:1 @ wide open throttle. After the first 120 minutes, the oil ratio changes to 120:1
@ idle and 50:1 @ wide open throttle.
Final Checks Before Operation of Engine
•
Make sure fill cap gaskets are in place and caps are tight on engine oil reservoir and
remote oil tank.
•
Be certain the warning horn is installed and is operational. Refer to Instrument and
Warning Horn Installation.
•
Each time the key switch is turned from the “OFF” to “ON” position (engine not run-
ning); the warning horn will sound momentarily. This tells you the warning system for
the oil injection system is functional and the warning horn is operational. If warning
horn does not sound or horn stays on when key is turned to the “ON” position, refer to
oil injection system troubleshooting chart following to correct the problem.
Checking Operation of the Oil Injection System (Engine Running)
1. Operate engine following the break-in procedure outlined in the Operation and Main-
tenance Manual. If warning horn should sound an intermittent “beep,” “beep,” “beep”
during operation, this indicates low oil level in the engine mounted oil reservoir. Refer
to troubleshooting following, to correct the problem.
2. After engine has been run for a short time, check that no oil is leaking out of engine
oil reservoir fill cap.