Versatile platform that's a great fit for everything from runabouts to pontoons to houseboats

  • Ample power for a range of pursuits, from towing skiers and tubers on an 18-foot runabout to dual-engine applications on a larger cruiser
  • Durable V6 configuration affords trouble-free ownership and delivers impressive torque for quick acceleration and planing
  • Can be paired with Alpha One drive - the most popular sterndrive in the world - or Bravo drives, excellent for cruising applications
  • SeaCore offers unmatched corrosion protection thanks to industrial hardcoat anodizing, stainless steel components, exclusive low-copper alloy and other advances
Power You Can Count On

MerCruiser's 4.3L sterndrives are built to give you that classic Mercury burst with the stamina to run all day long, and then some. The strapping V6 design lends toughness, power, and efficiency, while ensuring reliable, purring starts every time. Put that all together, and you've got a rock-solid package that's ready for liftoff.

High Tech, Low Stress

You want the performance without the headaches.That's why Mercury is committed to developing innovative and sound technology that contributes to a more seamless boating experience. MerCruiser's 4.3L sterndrives feature Engine Guardian technology that monitors your engine's vitals to help protect your investment for the long-run; power steering reduces the effort needed for steering while providing enhanced hull control at all speeds. Now, that's more like it.

Driven to Perform

A MerCruiser 4.3L engine can team up with several of Mercury's popular drives - including Alpha and Bravo - for robust long-term durability. Standard on Bravo drive models and available on Alpha One drives, Mercathode Corrosion Protection is an active cathodic corrosion-protection system that feeds electrons to underwater hardware and drive units, bolstering your sterndrive's toughness against the corrosive wear and tear of regular use.

4.3 MPI ECT Specifications

HP/kW 220 / 164
Full throttle RPM 4400-4800
Cylinder Configuration V-6
Displacement (L) 4.3
Weight 775lbs
352kg
Dimensions (L x W x H) 28in x 30in x 22in
696mm x 740mm x 559mm
Bore and Stroke (in / mm) 4.00 x 3.48in
101 x 88mm
Ignition Crank fired high voltage switch with knock control
Alternator Amp 65 amp / 917 watt
Cooling Systems Raw water
Thermostatically controlled
Accessory Drive Systems Serpentine belt
Water Drain Systems Single point manual drain (Alpha)
Three-point manual (Bravo)
Exhaust System Iron manifolds with electro-deposition paint coated dry joint exhaust elbow
Recommended Oil Mercury MerCruiser Full-Synthetic Engine Oil, 20W-40, NMMA FC-W rated
Recommended Fuel 87% octane / up to 10% ethanol
Engine Control System ECM 07 with SmartCraft CAN capability
Engine Guardian System High coolant temperature
Knock control
Low drive lubricant
Low oil pressure
Low sea water pressure
Low voltage
Over-rev
Fuel Delivery Systems Cool Fuel
Emissions Control Technology Yes*
Boat Types Deckboat
Fish
Pontoon
Runabout (cuddy)
Runabout (open bow)
Sportboat (sterndrive)

4.3 TKS - Available in limited quantities / select regions. Consult your local dealer for availability.

4.3 MPI - *Non-catalyzed models available for select international markets. Consult your local dealer for availability.

4.3L Engine Tests

There are currently no engine tests for this product line.

4.3L Resources

Buy the Books

You can order all available Mercury literature online or through any authorized Mercury dealer. Please have your outboard or sterndrive serial number before placing the order.

  • Operation, Maintenance and Warranty Manuals
  • Parts Manual
  • Service Manual
Purchase a Manual
Request a Brochure

Request printed brochures by mail or download as an electronic PDF.

Request a Brochure
Installation Drawings

Installation drawings are technical documents, detailing the dimensions of the engines to facilitate installation in new or repowered boats.

Installation Drawings

Alpha One Drive

The most popular sterndrive in the world. Single/twin applications up to 65 mph for gas engines up to 300 hp

The Alpha® One drive earned the title of "world's most popular sterndrive" because it delivers reliable performance in a value package. reliable performance means more family fun year after year without missing a beat. Alpha One drives slice through the water with an efficient hydrodynamic profile producing very little drag. And, because of the Alpha drive's many maintenance-free features, you'll enjoy a worry free ownership experience.

Bravo One

Great performance starts with heart. Bravo! Single/twin/triple applications over 100mph for gas engines up to 600 hp

The Bravo One drive delivers superior performance with best-in-class shifting. Its exclusive performance torpedo design and dual water pickups allow for speeds topping the century mark, with exceptional handling at high and low speeds. A trim-limit switch sets your drive angle for maximum performance every time, and a greaseable drive coupler allows for quick and easy service without removing the drive unit.

Bravo Two

Handle the biggest boats with authority. Twin applications up to 55 mph for gas engines up to 450 hp

The unique Bravo Two drive has an unmatched ability to maximize lift and thrust for cruisers and houseboats without breaking a sweat. Due to the girth of the gearcase, Bravo Two is capable of accommodating a huge 20-inch diameter prop with deeper gear ratios. This allows the Bravo Two to deliver high thrust around the dock, quick planing and improved fuel economy-putting you in control. maintenance-free hinge pins allow for easy service without having to pull the boat from the water.

Bravo Three

Efficient.Maneuverable. Unbeatable. Single/twin applications up to 65mph for gas engines up to 525 hp

The twin-prop design says it all. Whether in a single-unit or twin-unit application, the Bravo Three is an efficient drive built without compromise. Perhaps it's the best-in-class shifting or its counter-rotating propeller design - enabling agile handling in reverse for precision maneuverability. And the greaseable gimbal bearing makes for an easy ownership experience-allowing for service without removing the drive unit. The Bravo Three X drive, standard on big block 8.2L high-output engines, is a superstrength drive with high performance attributes.

Axius SeaCore Emissions Control Technology Sustainability Report Fuel Care