HawaiiOutboard Repair
(808) 824-4380 Request service
MenuClose

Mercury OptiMax 225 Pro XS / 225 Sport XS (3.0 L, 2005 on) service guide

Oil, gear oil, spark plugs and the service schedule for the Mercury OptiMax 225 Pro XS / 225 Sport XS (3.0 L, 2005 on) (225 hp, two-stroke), from the factory service manual, plus how we service it in Hawaiʻi.

Models covered: Mercury 225 Pro XS OptiMax (Torque Master gearcase), starting model year 2005, serial 0T997974 and above; and 225 Sport XS OptiMax (Sport Master gearcase), starting model year 2006, starting serial no. 1E000797. 60° V6 direct fuel injection 2-stroke, 3046 cc (186 cid).

Quick answers

What two-stroke oil does a Mercury OptiMax 225 Pro XS / 225 Sport XS use?
Premium Plus 2-Cycle TC-W3 Outboard Oil. Engine oil tank 0.84 liters (0.88 US qt); in-boat oil tank 11.4 liters (3 US gal).
What gear oil does a Mercury OptiMax 225 Pro XS / 225 Sport XS use, and how much?
High Performance Gear Lubricant.
What spark plug does a Mercury OptiMax 225 Pro XS / 225 Sport XS use?
NGK IZFR6J, gap 0.81 mm (0.032 in); qty 6.
How often should a Mercury OptiMax 225 Pro XS / 225 Sport XS be serviced?
The factory schedule lists: Every 25 hours or 30 days; Every 50 hours or once a year; Every 100 hours or once a year; Every 200 hours or once every two years. In Hawaiʻi's salt water we do a full yearly service every 200 hours or 1 year, whichever comes first, and a new engine needs its first (break-in) service.
When should the water pump impeller be replaced on a Mercury OptiMax 225 Pro XS / 225 Sport XS?
The factory schedule says to replace it at 100 hours and 200 hours, and we follow that. In any case we never let it go longer than a year in Hawaiʻi's salt water.
What is the idle speed of a Mercury OptiMax 225 Pro XS / 225 Sport XS?
575 RPM. Full throttle 5500 to 6000 RPM.
What is the propeller nut torque on a Mercury OptiMax 225 Pro XS / 225 Sport XS?
75 N·m (55 lb·ft).

Maintenance specs

Injection oilPremium Plus 2-Cycle TC-W3 Outboard Oil. Engine oil tank 0.84 liters (0.88 US qt); in-boat oil tank 11.4 liters (3 US gal)
Gear lubeHigh Performance Gear Lubricant
Fill and vent screwsVent screw 7 N·m (60 lb·in); fill screw 7 N·m (60 lb·in); both gearcases. Replace the sealing washers if damaged. On the Torque Master the fill screw is in the bearing carrier
Gearcase pressure test (before filling)69 to 103 kPa (10 to 15 psi) through the vent hole (tester FT8950); steady for at least 15 seconds while working the shift shaft fore and aft
Spark plugNGK IZFR6J, gap 0.81 mm (0.032 in); qty 6
Spark plug torqueFinger tight plus 1/4 turn, or 27 N·m (20 lb·ft)
Idle speed (in gear)575 RPM. Full throttle 5500 to 6000 RPM
ThermostatOpening temperature 54 °C (130 °F)
Water pressureMinimum at idle 14 kPa (2 psi); minimum at WOT 69 kPa (10 psi); maximum at WOT 172 kPa (25 psi); poppet valve opening 41 kPa (6 psi)
Water separating fuel filterReplace every 200 hours or once every two years. Under a cap on the vapor separator; oil the O-ring seals, tighten securely, squeeze the primer bulb firm and check for leaks
Propeller nut75 N·m (55 lb·ft)
Power trim fluidPower Trim and Steering Fluid or Dexron III ATF. Level even with the bottom of the fill hole, tilted full up. Maximum leak-down 25 mm (1 in) in 24 hours
Alternator beltCheck tension every 25 hours or 30 days; inspect all belts, pulleys and idler pulleys every 50 hours or once a year. Grease the belt tensioner arm through its fitting

Service schedule

The factory maintenance intervals, with what is replaced and what is checked at each. Rows marked Hawaiʻi are our shop's yearly service for salt water use.

  1. Every 25 hours or 30 days

    Replace: gear case plug gaskets

    Check: gear case oil, drive belts, anodes

  2. Every 50 hours or once a year

    Replace: gear case oil, gear case plug gaskets

    Check: spark plugs, drive belts, anodes

  3. Every 100 hours or once a year

    Replace: gear case oil, gear case plug gaskets, water pump impeller

    Check: spark plugs, drive belts, anodes

  4. Every 200 hours or once every two years

    Replace: fuel filter, gear case oil, gear case plug gaskets, water pump impeller

    Check: spark plugs, drive belts, anodes

Source: Mercury 225 Pro/Sport XS OptiMax service manual, 90-841916R01. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.

Other Mercury guides