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Grove Harbour Marine
2017 Mercury MerCruiser 4.5L 250HP ECT
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The Next Generation

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.

Standard Features
  • Built for Marine
    Designing a V-6 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 aluminum and composites everywhere else.
  • Corrosion Protection.
    The MercFusion Paint System creates an outer seal against the elements, while MerCathode® provides automatic protection against galvanic corrosion. For maximum defense against saltwater effects, the SeaCore® industrial hardcoat anodizing system and closed-cooling circuit is available.
  • Easy to Maintain.
    When service is required, maintenance is a snap with the front-mounted drive lube monitor, color-coded maintenance points - including easy-to-reach oil filter and fill - and "how-to" videos that can be accessed via the QR code on the label.
  • Named Top Product by Boating Industry
    The Mercury Marine 4.5L 200hp sterndrive is a 2015 Boating Industry Top Product of the year.
    The winning products were selected based on many factors, including innovation, impact on the industry, and how they advanced their category or created a new category.
    In 2014, the Mercury MerCruiser 4.5L sterndrive engine was named an Innovation Award Winner at the International Boatbuilders Exhibition & Conference (IBEX).
  • Powerful Performer.
    Thanks to its new, long-runner scroll intake manifold which draws in more air and converts it into additional torque, the 4.5L delivers a ground-breaking power-to-weight ratio and gives you V-8 power in a V-6 package.
  • Repower Financing.
    With Mercury Repower Financing, you can easily power up everything from fishing boats, to runabouts, to cruisers with flexible financing on the engine. You can also choose to finance rigging, gauges, controls and even labor. Mercury Repower Financing offers low rates and low monthly payments to fit a boater's budget.
  • Smooth & Quiet.
    The 4.5L'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. Resulting in an exceptional driving experience.
  • 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.
Engine Specs
Max RPM (WOT)4800-5200
Engine TypeV6, 2-valve/cylinder pushrod
Bore & Stroke (in/mm)4.0 x 3.6" / 102 x 92 mm
Lubrication SystemIntegrated wet sump
Cooling SystemWater cooled with thermostat; FWC available as factory option (Alpha) and packaged with SeaCore Drive (Bravo)
Ignition SystemSmartCraft PCM 112 Digital Inductive
Engine Guardian SystemSmartCraft Engine Guardian
Recommended OilNMMA Certified FCW 25W-40 Synthetic Blend
Engine Control SystemMechanical Shifting with Optional SmartCraft DTS
Standard SmartCraft with Electronic Throttle Control
Fuel Requirements90 RON 10% Ethanol Maximum
Unleaded Regular 87 Octane Minimum (R+M/2)
Fuel Delivery SystemComputer controlled Multi-Port Electronic Fuel Injection (MPI)
Water Drain SystemAir Actuated "Season Extender" (Bravo)
Easy Drain "Season Extender" (Alpha)
Exhaust SystemThrough prop
Displacement275 / 4.5 (CID/L)
Compatible drivesAlpha
Bravo One
Bravo Three
Bravo Two
Weight (engine only)761 lbs / 345 kg
Displacement (L)4.5
HP / kW250 / 186
Air Induction SystemPerformance-Tuned Scroll Intake Manifold
Dimensions (L x W x H)28 x 30 x 22" / 696 x 740 x 559 mm
Fuel Ethanol ToleranceUp to 10%
Recommended FuelUnleaded Regular 87 Octane Minimum (R+M/2) or 90 RON 10% Ethanol Maximum
Alternator Amp / Watt70 amp / 882 watt (Belt-Driven)