Mercury Racing offers fuel-injected drag outboard

FOND DU LAC, Wis. — Mercury Racing's all-new Mercury 2.5 EFI Drag race outboard was developed for American Power Boat Association sanctioned Outboard Drag Boat Association Modified Production class racing.

The compact 2.5 Liter V-6 powerhead cranks out more than 300 propshaft horsepower. Powerhead enhancements include the use of O-ring-sealed cylinder heads for improved heat transfer. This innovation, in addition to an external cylinder block cooling system, results in improved engine efficiency and durability.

Similar to the 2.5 Liter Mercury Formula 1 race outboard used in the Union International Motonautique Formula One World Championship Series, the 2.5 EFI Drag race powerhead comes standard with a Brucato Stackable Velocity System high- performance intake system modified by Mercury Racing. The addition of twin balance tubes enhances the balance of air between cylinders, resulting with improved low speed throttle response for superior hole-shot and acceleration. A sliding throttle plate provides an unobstructed opening at wide open position, allowing an undisturbed airflow for maximum top-end speed.

Adjustable velocity stacks allow tuning of peak torque at a specific rpm, taking advantage of the expansion and compression waves that naturally occur in a two-cycle engine. The unequal length of the velocity stacks enhances mid-range acceleration and top-end speed. The modified SVS system is complimented with a seven-petal intake system fed by a digital Electronic Control Module and six individual fuel injectors, for quick starting and optimal engine performance throughout the 9000 rpm operating range.

New hardened and beveled crankshaft seal rings, standard on all 2001 Mercury 2.5 EFI models, provide a better seal for improved durability. To draw more power out of the 153 CID cylinder block, engineers raised the cylinder exhaust porting profile. New single ring pistons feature a vertical piston ring stake pin. A special coating on the piston rings provides lubrication for cooler engine operating temperature. The use of vertical piston ring stake pins and coated rings enhances engine reliability.

Machined connecting rods, featuring new high performance wrist pins, reduce engine weight. The machined rods, along with a lightweight aluminum flywheel, also extend crankshaft and upper crank bearing life. The new 2.5 EFI Drag race outboard features the lightweight Formula One race top cowl. The cowling features cooling louvers and quick release rubber latches.

Mercury 2.5 EFI Drag race outboards are available with the 15 inches short shaft center section. The short shaft center section lowers the engine's center of gravity, improving boat handling and overall performance. A two-inch setback built into the heavy-duty swivel bracket assembly improves the running angle of the boat, requiring less trim. Solid engine mounts improve boat handling and overall performance. Models come standard with the 1.87:1 Sport Master gearcase.

The Sport Master, featuring a satin-finished aluminum housing, provides superior hydrodynamics enhanced by a race-proven torpedo shape and a three-slot, low-water pickup design. The design features less frontal area for reduced drag while providing increased water flow. The pickups are designed to reduce the ingestion of weeds and other debris. A built-in torque tab on the skeg that reduces steering torque, improving control and overall boat performance. The Sport Master gearcase is designed to operate at transom heights of 27 inches to 30 inches (685 mm to 762 mm).

2.5 EFI Drag Race Specifications