FOR SALE 1998 Mercruiser 3.0 Drop In Engine 140 Hp. We have installed a new starter, test ram and compression tested this engine.

The 1998 MerCruiser 3.0L “drop-in” engine is a carbureted, inline-4 GM cast-iron block historically rated at 140 HP (propshaft rated at 135-140 HP depending on the specific 1990s generation). It remains one of the most reliable and common sterndrive packages on the water.

Core Specifications

• Horsepower : 140 HP @ 4,400–4,800 RPM (WOT)
• Displacement : 181 CID (3.0 Liters)
• Engine Type : Inline-4 cylinder, 4-stroke
• Bore & Stroke : 4.00 X 3.60 inches (101 X 91 mm)
• Compression Ratio : 9.3:1
• Ignition System : EST Analog Ignition (or breakerless distributor)
• Fuel System : 2-barrel carburetor (typically Rochester 2SE or MerCarb)
• Cooling System : Raw water cooled (thermostatically controlled)
• Dry Weight : Approximately 515 lbs. (234 kg)

Mechanical Details

• Block Material : Heavy-duty cast-iron (built specifically to withstand high marine loads and resist salt/brackish water).
• Valvetrain : Pushrod actuation with hydraulic lifters.
• Oil Capacity : 4.5 Quarts (with filter) of SAE 20W-40 or 25W-40 Marine Engine Oil.
• Spark Plugs : NGK BPR5ES (Gap set to 0.035 inches / 0.9 mm)