Tohatsu MFS115AETL 115HP 20in EFI Outboard Motor

Description

Need broad commercial torque? Select the Tohatsu MFS115AETL Marine Outboard Engine for harbor craft. Displacing 1995 cc across four inline cylinders, this 16-valve dual overhead cam powerhead generates 115 continuous horsepower at 5000 to 6000 RPM. Designed for 20-inch transoms, tuned exhaust headers combine with fuel injection to maximize acceleration.

Engineers cast the 2.0-liter powerhead from marine aluminum alloy with centrifugal cast iron cylinder liners. A 4-2-1 exhaust manifold routes exhaust pulses to scavenge spent combustion gases without backpressure. The 20-inch midsection houses heavy duty lower unit reduction gears establishing a 2.08 to 1 ratio. Base dry engine weight reaches 392 lbs. The wet sump lubrication reservoir stores 4.4 quarts of motor oil, supported by an integral water-cooled oil cooler.

Key Features of Tohatsu MFS115AETL

Commercial operators buy Tohatsu MFS115AETL outboard engine packages to power offshore survey ribs and harbor pilot vessels. 4-2-1 performance tuned exhaust headers generate highest-in-class torque to snap displacement hulls on plane.

• 4-2-1 tuned exhaust headers scavenge exhaust gases to produce massive mid-range torque.
• 2.08 to 1 gear reduction mechanisms swing broad diameter propellers for strong vessel acceleration.
• 20-inch driveshafts integrate with standard commercial deep-V boat transoms without structural bracket modifications.
• 35-amp alternators generate 28 amps at idle speeds to maintain heavy electronic battery loads.
• Dynamic idle speed adjustments allow operators to troll between 650 and 850 RPM with simple key clicks.
• Tohatsu MFS115AETL commercial vessel performance diagnostics broadcast live operating parameters straight to NMEA2000 screens.
• Dual freshwater flush ports allow thorough cooling passage descaling without starting the powerhead.

Combustion Dynamics Thermal Threshold Specifications

Calibrated thermostat regulators maintain engine coolant operating temperatures between 140°F and 160°F inside cylinder jackets. Operating at 9.5 to 1 compression, the 1995 cc powerhead generates 115 continuous horsepower at 5500 RPM under heavy commercial duty cycles. Precision knock sensors adjust spark advance curves to prevent detonation under sudden acceleration. High capacity centrifugal pumps drive raw seawater through block jackets to dissipate extreme combustion heat loads during continuous towing. Specific fuel consumption rates hold at 0.38 lb per brake horsepower hour within the lean cruise envelope.

Transom Installation Interface Geometry

Cast aluminum transom brackets mount with standard four-bolt patterns spaced across 20-inch transom planes. The through-propeller exhaust passage discharges spent combustion gases below water lines to keep decks clear of fumes. Heavy duty rubber shear mounts decouple engine harmonic vibrations from aluminum hull stringers and welded deck bulkheads during commercial runs.

Operational Protocols Service Maintenance

Mechanical shift linkages engage forward and reverse dog clutches without hesitation. Harbor operators inspect raw water pump telltale streams to confirm positive cooling flow before morning departures. This outboard motor is not engineered for pure racing hydroplanes, surface piercing mud props, or unventilated enclosed engine boxes.

• Check crankcase oil dipstick levels and inspect fuel filter bowls before each shift begins.
• Drain crankcase engine oil and replace lower gearcase lubricant every 100 hours of operation.
• Replace low pressure fuel filters and check external sacrificial zinc anodes every 12 months.

Commercial Warranty Crate Specifications

Tohatsu backs this powerhead with 3-year commercial or 5-year recreational limited warranty protection. The export transport crate includes the complete MFS115AETL outboard motor, remote steering linkage rod, transom mounting bolt package, fuel hose connector, spare spark plugs, and official factory operator technical maintenance binder.