Mercury 200 OptiMax Jet Drive, Service Manual, Page: 251 / 391

Oil Injection
Page 3C-6 90-8M0050731 MAY 2011
Oil System Operation
Oil is stored in an engine‑mounted reservoir and in a remote oil tank on the boat. Crankcase pressure forces oil from the remote
oil tank into the engine‑mounted oil reservoir. The engine oil reservoir feeds oil to the oil pump. The oil pump is actuated by the
PCM and distributes oil to the crankcase and air compressor. The oil pump has seven discharge ports with an oil delivery hose
attached to each discharge port. Six of the hoses are connected to check valves near the reed assembly. The check valves are
spring‑loaded and require 34.5–48 kPa (5–7 psi) to unseat the check ball. The seventh oil delivery hose is connected to the air
compressor for lubrication. Serial number 0T178499 and below, the air compressor has a single oil return port and is connected
to the top of the intake plenum. Serial number 0T178500 and above, the air compressor has two oil return ports. These two ports
return oil to the top and bottom main bearings on the engine.
The PCM is programmed to 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 operation whenever the engine is under a load. At idle the oil pump is providing oil at the normal
ratio. After the engine break‑in period has expired, the oil ratio returns to normal.
Oil Pump Output
Use the computer diagnostic system (CDS) to activate the auto prime. The oil pump should discharge approximately 100 ± 8 ml
(3 ± 0.2 oz) during the auto prime.
To check the oil pump output:
•
Verify the engine‑mounted oil reservoir is full.
• Release the pressure from the remote oil tank in the boat by loosening the cap.
• With the engine not running, use the CDS to activate the auto prime.
• Use a ml or cc graduated container to record the amount of oil needed to fill the engine mounted oil reservoir.
• Tighten the cap on the remote oil tank in the boat.