Mercury 2013 OptiMax 300 XS
Standard Features


The World's Most Powerful 2-Stroke Low Emissions Outboard

Mercury Racing is all about passion for perfection and the pursuit of peak performance. We have a reputation of exceeding consumer expectations in product quality and performance - something we've carried forward from the late Carl Kiekhaefer, Mercury Racing president Fred Kiekhaefer's father and founder of Mercury Marine. The all-new OptiMax 300XS outboard continues our heritage of delivering more power and performance than competitors with the same horsepower rating.

The heart of the new 300XS "Stroker" is a 3.2 liter V-6 powerhead featuring a stroked and precision-balanced crankshaft for maximum power and performance. A dampener ensures smooth running throughout the engine operating range. New pistons feature an updated profile and a composite coating for improved wear life. Piston ring life is doubled thanks to a composite chrome coating.

The exhaust port, combustion chamber and fuel induction designs are direct descendants from our Formula 1 tunnel boat race engine. Airflow through the reed block fuel induction system is enhanced due an enhanced air box design along with thinner reed material and the unique reed shape developed for Formula 1 racing.

As with the complete line of Mercury Racing OptiMax XS outboards, the 300XS comes with a heavy-duty direct fuel injection air compressor featuring robust maxi-coated mounting brackets and hardware for enhanced compressor durability and reliability.


Model Year
OptiMax 300 XS
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Engine Type
V-6 (60° vee)
300 hp (224 kW)
193 ci (3,160 cc)
Bore x Stroke
3.63 x 3.11 in. (92 x 79 mm)
5,400 - 5,800
5,400 - 6,100 on 20 in. models
Fuel Induction
2-stage direct fuel injection
Electronic multi-point
PCM digital inductive


Gear Ratio
1.62:1, 1.75:1 (SM), (TM) or 1.75:1 (FM)


60A, 756W with voltage regulator


Shaft Length
20, 25 or 30 in. (508, 635 or 762 mm)
(L) 505 lbs. (229 kg) / (XL) 517 lbs.(235 kg) / (XXL) 534 lbs. (242 kg)

Standard Features

 3.2 l V6 powerhead features stroked and balanced crankshaft for maximum displacement and performance.  
 Extensive research and development result in a Formula 1 race-based exhaust porting and reed block fuel induction design for top power.  
 New combustion chamber design results in the engine producing peak power longer at the upper end of the operating rpm range.  
 A unique 2-stage direct-injection system atomizes fuel into small, uniform particles, resulting in complete and instantaneous combustion.  
 Fuel / air mixture is injected into the combustion chamber at 95 psi (15 psi higher fuel / air differential than standard DFI or OptiMax product) for enhanced high rpm running quality.  
 New PCM microprocessor features a 14-pin Deutsch connector harness which incorporates engine ignition and SmartCraft CAN (controller area network) wiring in one connector.  
 The SmartCraft Engine Guardian system monitors engine functions for early indications of problems that could lead to engine damage.  
 The 60A, belt-driven alternator is the most powerful in its class.  
 Electronic multipoint lubrication system delivers precise amounts of oil where and when it’s needed.  
 Acoustically-tuned foam cowling wrap and new exhaust bucket design results with quieter engine sound throughout the operating range.  
 Through-hull Noise Vibration Harshness (NVH) levels are further reduced on 25 and 30 in. models thanks to the use of softer upper and lower engine mounts.  
 A new exhaust system, along with a foam-lined cowl and attenuator for the compressor, greatly reduces the operating Dba.  
 Torque Master, Sport Master and new Heavy-Duty Fleet Master gearcases enhance the versatility of the world’s most powerful available for virtually any application.  
*Price, if shown, is Manufacturer's Suggested Retail Price (MSRP) and does not include government fees, taxes, dealer freight/preparation, dealer document preparation charges or any finance charges (if applicable). MSRP and/or final actual sales price will vary depending on options or accessories selected.