The 100 Amp Trim Pump Fuse from Buckshot Racing #77 is a rugged, marine-rated replacement for multiple Mercury OEM fuse part numbers, including 878230, 79023, 79023A10, and 79023T10.
Designed to handle high current loads in trim and tilt circuits, this fuse is essential for protecting the hydraulic trim pump systems found in a wide range of Mercury Marine and Mercury Racing outboards.
With its heavy-duty red thermoplastic body and corrosion-resistant brass terminals, the Buckshot Racing #77 fuse is engineered for long-term reliability in demanding marine environments.
It features a 5/16-inch mounting hole (8mm metric equivalent) and a 10mm threaded post that accepts standard 1/4-inch ring terminals, making it a direct-fit, bolt-on replacement for the Mercury 100A trim pump fuse across both legacy and modern outboard platforms.
This fuse plays a vital role in the electrical systems of some of the most iconic and powerful outboards ever made. It’s used in Mercury Racing 2.5L models like the 260 EFI, 280 ROS (Race Offshore), 300 Drag, 245 HP Carbureted, and 200 HP 2.5L carb or EFI variants.
These engines are the heart of performance river racers, drag boats, and offshore hulls—boats that demand rock-solid reliability from every system, especially the trim circuit.
It’s also found in larger platforms like the 300X (3.0L EFI Pro Max), 250 HP XS 6-CYL (3.0L), and 300 HP XS 6-CYL (3.2L), all of which are high-output motors designed for serious speed and control.
And for today’s cutting-edge models, the Buckshot Racing #77 is a trusted component in the Mercury Racing 4.6L V8 outboards, such as the 250R and 300R , where trim system performance must match the muscle of the engine.
What makes this fuse unique is its installation flexibility. While it can be mounted to a hull bracket using the molded eyelet, many installers choose to mount it directly to the trim pump solenoid’s 5/16-inch threaded input post.
This inline configuration reduces wiring length, lowers resistance, minimizes corrosion points, and simplifies the entire circuit. It’s a method that’s become standard on performance boats and custom rigging setups, especially when tight rigging and maximum current efficiency are priorities.
Installation Instructions
Disconnect the battery. Remove any existing fuse (such as one labeled 878230, 79023, 79023A10, or 79023T10), and route your battery's positive cable to one terminal of the Fuse. Then, bolt the fuse directly to the solenoid’s 5/16" power input terminal, securing the ring lugs firmly and using dielectric grease to prevent corrosion. Once connected, this fuse will protect your trim pump motor from overcurrent and short circuits with unmatched dependability.
Beyond high-performance models, this style fuse is also used in popular Mercury outboards like the V-150, V-200, 200 EFI Pro Max, 225 EFI, and 250 EFI. It meets ABYC compliance standards, providing safe, approved overcurrent protection when placed within seven inches of the power source—crucial for systems with battery switches or batteries rated over 800 cold-cranking amps.
Whether you're dialing in a 300 Drag 2.5L, restoring a 260 EFI, maintaining a classic 300X (3.0L Pro Max), or powering into the future with a 300R 4.6L V8 Racing, this fuse is your frontline defense.
It replaces all variations of the Mercury 100 trim fuse: 88-878230, 79023, 79023A10, and 79023T10. Trusted in everything from high-performance bass boats to offshore racers, our fuse is the no-compromise solution for protecting your trim system and keeping your engine at peak readiness.
Contact Mike Hill at +1-714-697-1716 or email mike@buckshotracing77.com for technical support.