Optimum everything.

OptiMax 1.5L outboards deliver the gutsy power of direct fuel injection to small and midsized boats. Like the higher-horsepower models, the 75, 90 and 115 hp OptiMax churn out high-intensity power with clean, quiet fuel efficiency. They’re lightweight, they provide spectacular acceleration, and they use surprisingly little gas. When you factor in the reliability and durability of OptiMax, it’s easy to see why so many serious boaters run OptiMax.

Quiet, please!

Mercury OptiMax is significantly quieter than conventional two-stroke outboards. Thanks to an exclusive air bypass silencer, sound level at idle is nearly as quiet as a four-stroke.

Ultra, ultra, ultra clean.

Mercury OptiMax 75, 90, 115, 135 hp and 225 Pro XS all earn CARB three-star ultra-low emissions grades. All other OptiMax models register a respectable two-star rating.

OptiMax 90

Mercury OptiMax 1.5L engines are up to 18% more fuel-efficient than competitive four-stroke and two-stroke DFI engines.

Specifications HP @ Prop: 90 kW @ Prop: 66.2 Max RPM (WOT): 5000-5750 Cylinder/Configuration: 3 (in-line) Displacement (CID/cc): 92.96/1526 Bore & Stroke (in): 3.63 x 3.00 Bore & Stroke (mm): 92 x 76 Cooling System: Water-cooled with thermostat & pressure-controlled Ignition System: PCM 038 Starting: Electric Gear Ratio: 2.33:1 Gear Shift: F-N-R Steering: Remote Alternator: 60-amp/756-watt belt-driven Trim System: Power trim Exhaust System: Through prop Lubrication System: Electronic multipoint oil injection Recommended Oil: Mercury OptiMax/DFI Engine Oil Fuel Induction System: 2-stage direct fuel injection Shaft Length (inches): 20/25 Shaft Length (mm): 508/635 Dry Weight (lbs.): 375 Dry Weight (kg.): 170 Operator Warning System: Overheat, low oil level SmartCraft: Yes CARB Star Rating: 3 Warranty: 3