AMSOIL Synthetic 2-Stroke Outboard Oil delivers clean-burning, low-smoke protection for water-cooled outboards, personal watercraft, and jet boats that call for TC-W3 oil. It fights plug fouling, carbon deposits, and the rust and corrosion that come with life on the water.
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Product data sheets
View, download, or save a copy of the Product Data Sheet or Safety Data Sheet for AMSOIL 100:1 Pre-Mix 100% Synthetic 2-Stroke Outboard Oil.
AMSOIL 100:1 Pre-Mix 100% Synthetic 2-Stroke Outboard Oil is the TC-W3 pre-mix synthetic for water-cooled two-stroke outboard motors, personal watercraft, and jet boats that call for an NMMA TC-W3 oil. The 14.5 cSt at 100 C synthetic formulation is built around low-temperature dispersants and a smokeless, low-odor combustion chemistry, and it is engineered to protect at lean 100:1 mix ratios so it delivers fewer emissions at 100:1 than other oils mixed at 50:1.
NMMA TC-W3 protection at lean 100:1 pre-mix ratios
The synthetic base oils and anti-wear additive system are tuned to deliver superior lubricity and anti-wear protection at 100:1 mix ratios, which works out to 1.3 oz of oil per US gallon of gas. That lean ratio cuts the volume of oil burned in the cylinder while still meeting the NMMA TC-W3 standard for water-cooled two-stroke engine protection, so it works in the older carbureted Mercury, Johnson, Evinrude, Yamaha, and Suzuki outboards that grew up on pre-mix as well as in newer TC-W3 equipment.
Kinematic viscosity of 14.5 cSt at 100 C and 111.2 cSt at 40 C with a viscosity index of 133 per ASTM D445 and ASTM D2270 keeps the film between the piston, rings, and cylinder wall under load, even when the carbs are tuned lean and the oil charge per gallon is small.
Low-temperature dispersants stop plug fouling and ring sticking
Two-stroke outboards burn oil in the combustion chamber, so the oil chemistry has to clear deposits before they form into varnish or hard carbon on the plug nose, ring lands, and exhaust ports. The formulation pairs synthetic base oils with low-temperature dispersants that suspend the partial combustion byproducts produced during idle, trolling, and cold morning starts and carry them out the exhaust rather than letting them harden inside the engine. The result is fewer fouled plugs, less ring sticking, and clearer exhaust ports on long-running outboards that idle and troll between holes.
Smokeless, low-odor combustion at the dock and on the troll
Trolling and no-wake zones expose two-stroke owners and their passengers to the exhaust the boat is making, and conventional pre-mix oils mixed at 50:1 are usually the source of that haze and that distinct two-stroke smell. The oil is engineered to burn clean to minimize smoke and emissions and to keep odor down, which matters when an aluminum boat or pontoon is sitting in a no-wake zone on a still day. The low-toxicity chemistry produces fewer emissions at 100:1 than other oils mixed at 50:1, so a fishing day with kids on board is easier on lungs and on water.
Rust and corrosion control built for marine service
Outboards face wet starts, salt air, and idle periods that let water condense in the crankcase, all of which accelerate rust on bearings, pins, and cylinder walls. The formulation inhibits rust and corrosion common to marine applications, so the bottom end and rotating assembly stay protected during off-season storage and between outings. The same chemistry also helps stabilize idle quality and maintain the rapid throttle response and ignition behavior that water-cooled two-stroke outboards rely on for hole-shot performance.
Recommended applications and service intervals
This oil is built to be pre-mixed with gasoline in water-cooled two-stroke outboard motors, personal watercraft, and jet boats that specify a TC-W3 oil. For maximum performance, mix with gasoline at 100:1 regardless of the mix ratio specified for the equipment. Richer mix ratios may be used if desired. Verify application match for the specific outboard, year, and horsepower with the AMSOIL Vehicle Lookup Guide before ordering.
100:1 pre-mix: 8.0 oz of oil per 6 US gallons of gas (1.3 oz per gallon) delivers TC-W3 protection at the lean ratio.
80:1 pre-mix: 8.0 oz of oil per 5 US gallons of gas (1.6 oz per gallon) is a richer setting many owners use during break-in.
50:1 pre-mix: 2.6 oz of oil per 1 US gallon of gas is the standard rich ratio carried over from older outboard manuals.
Use the pre-mix bottle for water-cooled TC-W3 outboards, personal watercraft, and jet boats; oil-injection outboards that call for TC-W3 are better served by a dedicated injector oil.
Aftermarket oil additives are not recommended for use with AMSOIL synthetic two-stroke oils. Pair the pre-mix bottle with a clean fuel container, a fresh fuel filter, and a stable ethanol-free or treated fuel, and review pre-mix versus oil-injection oil choices in the Marine 2-Stroke Oil Guide.
Typical technical properties
Property
Value
Kinematic Viscosity at 100 C, cSt (ASTM D445)
14.5
Kinematic Viscosity at 40 C, cSt (ASTM D445)
111.2
Viscosity Index (ASTM D2270)
133
Pour Point, C (F) (ASTM D97)
-37 (-35)
Flash Point, C (F) (ASTM D92)
174 (345)
Fire Point, C (F) (ASTM D92)
234 (453)
Order AMSOIL 100:1 Pre-Mix 2-Stroke Outboard Oil
AMSOIL 100:1 Pre-Mix 100% Synthetic 2-Stroke Outboard Oil is available in an 8 oz. bottle (ATOBC-EA), a case of 12 8 oz. bottles (ATOBC-CA), a quart bottle (ATOQT-EA), and a case of 12 quart bottles (ATOQT-CA). The product is Warranty Secure, which means it is a high-performance replacement for vehicle manufacturer-branded products and is backed by the AMSOIL Limited Warranty (G1363). Match the outboard, year, and horsepower to the correct two-stroke oil with the AMSOIL Vehicle Lookup Guide, compare pre-mix and oil-injection marine options in the Marine 2-Stroke Oil Guide, then order AMSOIL 100:1 Pre-Mix 100% Synthetic 2-Stroke Outboard Oil.
TC-W3 is the National Marine Manufacturers Association service category for water-cooled two-stroke outboard oils. An oil that carries the TC-W3 designation has passed the NMMA performance tests for lubricity, anti-wear protection, deposit control, and exhaust cleanliness in pre-mix water-cooled outboard service. AMSOIL 100:1 Pre-Mix 100% Synthetic 2-Stroke Outboard Oil is engineered to meet the TC-W3 standard at 100:1 mix ratios.
What does 100:1 mean and is it really safe for an outboard?
100:1 is a pre-mix ratio of 1 part oil to 100 parts gas, or 1.3 oz of oil per US gallon of gas. The oil is engineered to deliver superior lubricity and anti-wear protection at that lean ratio, and the application instructions call for mixing at 100:1 regardless of the mix ratio specified for the equipment. Richer mix ratios such as 80:1 or 50:1 may be used if desired, which is how most owners run during break-in or in hard-loaded service.
Will this oil work in an older Mercury, Johnson, Evinrude, Yamaha, or Suzuki carbureted outboard?
Yes. Carbureted two-stroke outboards from Mercury, Johnson, Evinrude, Yamaha, and Suzuki that originally specified a TC-W3 pre-mix oil are the primary application. Run the bottle at 100:1 for maximum performance or richer if the original owner manual called for 50:1 and the engine has been kept on that ratio.
Can this oil be used in oil-injected outboards?
This bottle is engineered for pre-mix use in water-cooled outboards, personal watercraft, and jet boats that specify TC-W3. Oil-injection outboards that share the same TC-W3 service spec are better served by a dedicated injector-grade marine oil; review the pre-mix versus oil-injection comparison in the Marine 2-Stroke Oil Guide before choosing.
Can it be used in chainsaws, weed trimmers, or other small 2-stroke equipment?
The bottle is designed and tested as a TC-W3 marine 2-stroke oil for water-cooled outboards, personal watercraft, and jet boats. Handheld air-cooled equipment such as chainsaws and trimmers calls for an API TC or JASO FD oil and is better served by a dedicated handheld two-stroke product such as AMSOIL Saber Professional rather than a TC-W3 marine oil.
Does using this oil void the factory warranty?
No. AMSOIL 100:1 Pre-Mix 100% Synthetic 2-Stroke Outboard Oil is Warranty Secure, which means it is a high-performance replacement for vehicle manufacturer-branded products and is backed by the AMSOIL Limited Warranty. Using AMSOIL synthetic lubricants does not void a new vehicle or equipment manufacturer warranty.
