The replacement wiring harness for Mercury Racing V6 2-stroke outboards with electronic control units (ECUs) using side-draft EFI injectors is a critical upgrade for high-performance marine engines. Precision-engineered and manufactured by the Wizard Race Shop, this harness is designed to deliver reliable electrical connectivity and durability under the extreme demands of racing and high-output boating applications.
This harness is a direct-fit solution for a range of Mercury Racing outboards equipped with digital ECUs and side-draft electronic fuel injection systems. It is compatible with the Mercury 260 HP, 260 ROS (Race Offshore), 280 Race, 280 Consumer, S3000, F1, Champ, and 300 Drag models.
These engines, renowned for their aggressive performance and responsiveness, necessitate a wiring system that ensures stable power delivery and maintains clean signal paths to support critical functions such as fuel delivery, ignition timing, and sensor feedback.
The harness replaces several OEM Mercury Hi-Performance part numbers, including 84-98866A19, 98866-A27, 98866, 98866A27, 98866A26, and 454-9602. It is a solution specifically targeted for the 2.5-liter and 2.0-liter V6 EFI engines that use the distinctive sixteen-pin ECU connector.
For Mercury Racing owners and builders seeking a high-quality, American-made replacement harness that meets or exceeds OEM standards, the Wizard Race Shop solution ensures reliable operation and long-term performance for some of the most iconic two-stroke racing engines ever produced.
Note: Mercury Hi-Performance had issued a technical note regarding the use of dielectric grease in these systems. It was determined that applying dielectric grease to the sixteen-pin ECU connector can interfere with proper electrical contact, particularly affecting the power supply to the electric fuel pump. As a result, Mercury Racing had officially discontinued the use of dielectric grease at this connection point across all applicable models using the digital ECU configuration.
Contact Mike Hill at mike@buckshotracing77.com or +1-714-697-1716 for tech support