Mercury / Mariner V6 135 / 150 / 175 / 200 / 225 two-stroke, carbureted and EFI (2.0 L and 2.5 L, 1992 to 2000) service guide

Quick answers

What two-stroke oil does a Mercury / Mariner V6 135 / 150 / 175 / 200 / 225 two-stroke, carbureted and EFI use?

Quicksilver TC-W3 2 Cycle Outboard Oil only.

What is the fuel to oil ratio for a Mercury / Mariner V6 135 / 150 / 175 / 200 / 225 two-stroke, carbureted and EFI?

Oil injected: gasoline with oil injection, gasoline/oil ratio 50:1 (25:1 break-in). Break-in: use a 50:1 (2%) gasoline/oil mixture in the first tank of fuel together with the oil injection; after that no oil is added to the gasoline.

What gear oil does a Mercury / Mariner V6 135 / 150 / 175 / 200 / 225 two-stroke, carbureted and EFI use, and how much?

Quicksilver Gear Lubricant, Premium Blend in the maintenance section; the lower unit section fills with Quicksilver Super Duty Lower Unit Lubricant. CLE, Sport Master and Torque Master gear cases: Quicksilver Hi-Performance Gear Lube. Quantity: 1.87:1, 2.00:1 and 2.30:1 gear cases: 22.5 fl oz (665.4 ml). 1.78:1 gear case (XR6 / Mag III 4-1/4 in. dia.): 21.0 fl oz (621.0 ml). Fill through the fill hole until lubricant flows out of the vent hole with no air bubbles.

What spark plug does a Mercury / Mariner V6 135 / 150 / 175 / 200 / 225 two-stroke, carbureted and EFI use?

NGK BU8H, surface gap, on all models except the 225 Pro Max and 225 Super Magnum, which use NGK BUZHW, surface gap; qty 6. Gap: Surface gap (not adjustable).

How often should a Mercury / Mariner V6 135 / 150 / 175 / 200 / 225 two-stroke, carbureted and EFI be serviced?

The factory schedule lists: Every 100 hours of use or once yearly, whichever occurs first. 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 / Mariner V6 135 / 150 / 175 / 200 / 225 two-stroke, carbureted and EFI?

The factory schedule says to replace it at 100 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 / Mariner V6 135 / 150 / 175 / 200 / 225 two-stroke, carbureted and EFI?

650 ± 50 RPM (105 / 140 Jet, 135, 150, 175, 200 carbureted, all EFI models, Pro Max / Super Magnum); 675 ± 50 RPM for the XR6 / Mag III. Idle mixture screw preset 1-1/2 ± 1/8 turns out on carbureted models, not adjustable on EFI.

What is the propeller nut torque on a Mercury / Mariner V6 135 / 150 / 175 / 200 / 225 two-stroke, carbureted and EFI?

55 lb ft (74.5 N·m); bend 3 tabs of the tab washer into the thrust hub grooves; after first use straighten the tabs, retorque to 55 lb ft and bend them down again.

Maintenance specs

Two-stroke engine oil	Quicksilver TC-W3 2 Cycle Outboard Oil only
Fuel to oil ratio	Oil injected: gasoline with oil injection, gasoline/oil ratio 50:1 (25:1 break-in). Break-in: use a 50:1 (2%) gasoline/oil mixture in the first tank of fuel together with the oil injection; after that no oil is added to the gasoline
Gear oil	Quicksilver Gear Lubricant, Premium Blend in the maintenance section; the lower unit section fills with Quicksilver Super Duty Lower Unit Lubricant. CLE, Sport Master and Torque Master gear cases: Quicksilver Hi-Performance Gear Lube
Gear oil quantity	1.87:1, 2.00:1 and 2.30:1 gear cases: 22.5 fl oz (665.4 ml). 1.78:1 gear case (XR6 / Mag III 4-1/4 in. dia.): 21.0 fl oz (621.0 ml). Fill through the fill hole until lubricant flows out of the vent hole with no air bubbles
Gear oil fill/drain screw and vent screw	Drain and fill screw (magnetic) and vent screw, each with a sealing washer: 55 lb in (6.0 N·m). Install the vent screw first, then the fill screw; do not lose more than 1 fl oz (30 cc) while refitting the fill screw. Use new washers as needed
Spark plug	NGK BU8H, surface gap, on all models except the 225 Pro Max and 225 Super Magnum, which use NGK BUZHW, surface gap; qty 6.
Spark plug gap	Surface gap (not adjustable)
Spark plug torque	20 lb ft (27.0 N·m)
Idle speed	650 ± 50 RPM (105 / 140 Jet, 135, 150, 175, 200 carbureted, all EFI models, Pro Max / Super Magnum); 675 ± 50 RPM for the XR6 / Mag III. Idle mixture screw preset 1-1/2 ± 1/8 turns out on carbureted models, not adjustable on EFI
Thermostat	143 °F (61.7 °C), one in each cylinder head; on test it must begin to open at 140 to 145 °F (60 to 63 °C). Water pressure 12 psi minimum at 5500 RPM
Fuel filter	Carbureted models: check the engine fuel filter for contaminants. EFI models: replace the water separating fuel filter
Anodes	Two on the gear case and one on the bottom of the transom bracket: replace before completely eroded; never paint or coat them
Propeller nut	55 lb ft (74.5 N·m); bend 3 tabs of the tab washer into the thrust hub grooves; after first use straighten the tabs, retorque to 55 lb ft and bend them down again
Power trim fluid	Quicksilver Power Trim and Steering Fluid; ATF Type F, FA, Dexron II or Dexron III may be used

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 100 hours of use or once yearly, whichever occurs first

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

   Check: spark plugs, anodes

2. Every 200 hours or 1 year (our Hawai‘i yearly service) Hawai‘i

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

   Check: spark plugs, anodes

Source: Mercury/Mariner 105/140 Jet, 135, 150, 175, 200, 225 service manual, 90-824052R3, June 2002. Specs can change by model year and serial number, so always confirm your exact model from the serial tag on the clamp bracket.