(a) Mercruiser 4.5L Petrol Engine 200hp Alpha Package



Mercury MerCruiser is proud to introduce the revolutionary new 4.5L sterndrive engine, designed specifically for marine use. Featuring a host of engineering innovations, the 4.5L series establishes new standards for power-to-weight ratio, driver experience, acceleration, durability, and ease of maintenance. Welcome to the next generation of MerCruiser sterndrives: powerful, proven and purpose-built.



  • This price includes complete sterndrive package and propeller.
  • Powerful Performer

Thanks to its new, long-runner scroll intake manifold which draws in more air and converts it into additional toruw, the 4.5L delivers a ground-breaking power-to-weight ratio and gives you V8 power in a V6 package.

  • Smooth & Quiet

The 4.5.L’s newly designed rear-facing throttle body, anti-whistle throttle plate, engine cover and mounts, lightweight flywheel, fuel-supply module, and structural oil pan all work together to deliver a superior idle, smoothness and low vibration. DTS is available on 4.5 Bravo model.

  • Sporty Handling

The 4.5L comes standard with Adaptive Speed Control, which automatically maintains engine rpm regardless of load or water conditions. The result is increased throttle response and a sporty feel.

  • Built For Marine

Designing a V6 block solely for marine use allows Mercury to build the 4.5L with the ultimate protection system, using cast-iron componentry where the engine intersects with seawater, and using corrosion-resistant aluminium and composites everywhere else.

  • A Purpose Built Power House

Lighter weight engines improve power-to-weight ratio and fuel efficiency. They also reduce the overall package weight of the boat, allowing it to take full advantage of the engine’s torque for quick acceleration and improved responsiveness.

  • Torque Displacement

At 4.5 litres, the new MerCruiser V6 has been sized to deliver the torque levels needed for class-leading acceleration while striking the perfect balance for smooth operation, light weight, and most importantly without increasing the package size over current MerCruiser 4.3L or 5.0L models.

  • Electronic Multi-Port Fuel Injection

EFI delivers the exact amount of fuel for all driving conditions. It also ensures reliable consistent starts, increased fuel efficiency, and better throttle response.

  • Electronic Throttle Body With Adaptive Speed Control (ASC)

The new throttle turns boating exhilaration up a notch. Holding RPM during hard turns allows the operator to keep both hands on wheel, which is not only safer, but makes for a more exciting and “sportier” driving experience. And holding a boat on plane at slow speeds is useful when navigating in following seas or in windy conditions, during tow sport activities, or whenever precision boat control is needed without a lot of speed. And with the electronic throttle body, acceleration is significantly more responsive and exciting.

  • Performance-Tuned Scroll Intake Manifold

The improved low and mid range air flow packs the air into the intake track to build power, leading to improved, torque in these engines, optimising boat acceleration and time to plane. More air means more power, that simple.

  •  New Circulating Water Pump

The all new circulating water pump will not only keep the engine running cool, it improves overall reliability and efficiency thanks to the use of more stainless steel components and easy access for maintenance. *Bravo Drive Models Only

  • Top-Mount 70 Amp Alternator

An extremely durable top-mounted alternator is also easy to access and service, but most importantly it keeps the critical battery charging function high and away from the bilge in a less corrosive environment, where water can’t accumulate.

  • Automatic Belt Tensioner

For the first time Mercury introduces the auto-belt tensioner to a V6 model. Maintaining constant tensions on the serpentine drive belt improves overall belt life and will minimise downtime for servicing, giving you more time to do what you enjoy doing most – being on the water.

  • Aft Facing Throttle Body

The intake opening is always the loudest part of any engine. By situating it Aft (facing the stern), engine noise is directed away from the boat, reducing noise in the cockpit area, allowing for normal conversation.

  • Lightweight Flywheel

Gear Shift quality has a direct impact on the perception of the overall engine package. The new 4.5L MerCruiser uses a lightweight flywheel, which generates far lower inertia, significantly reducing shift clunk and shock with a smoother shifting experience.

  • Anti-Whistle Throttle Plate

In the past, rapid airflow past the throttle body has sometimes caused a whistling noise as it hits the throttle blase. Not any more. A strategically placed deflector plate breaks up the air vortex completely eliminating noise, for a pleasing engine tone and enhanced ride.

  • Larger Engine Mounts

New front and rear engine mounts are larger which means they are significantly better at isolating undesirable engine vibration. The result is superior idle smoothness and lower vibration across the entire speed range.


Mercruiser Sterndrive and Inboard Brochure

Mercruiser 4.5L Alpha Installation Drawing




HP / kW
  • 200 / 149
Maximum RPM (WOT)
  • 4400 – 4800
Engine type
  • V6, 2-valve/cylinder pushrod
Displacement (L)
  • 4.5
Bore and stroke
  • 4.0 x 3.6″ / 102 x 92 mm
Fuel requirement
  • Unleaded 91 RON Minimum
Fuel delivery system
  • Computer controlled Multi-Port Electronic Fuel Injection (MPI)
Air induction
  • Performance-Tuned Scroll Intake Manifold
  • SmartCraft PCM 112 Digital Inductive
Alternator amp / Watt
  • 70 amp / 882 watt (Belt-Driven)
Water drain system
  • Easy Drain “Season Extender”
Exhaust system
  • Through prop
Cooling system
  • Water cooled with thermostat; FWC available as factory option
Lubrication system
  • Integrated wet sump
Recommended oil
  • NMMA Certified FCW 25W-40 Synthetic Blend
Dimensions (L x W x H)
  • 28 x 30 x 22″ / 696 x 740 x 559 mm
Weight (engine only)
  • 756 lbs / 343 kg
Compatible drives
  • Alpha


Please contact Sealink Marine for quote on freight.

Additional information