Sierra 18-6747

Upgrade Your Outboard's Performance with Reliable Tilt and Trim Control

Every boating enthusiast knows the frustration of a sluggish or unresponsive tilt and trim system. Whether you're navigating choppy waters or fine-tuning your propeller angle for optimal speed, a dependable assembly makes all the difference. The Sierra 18-6747 tilt/trim assembly steps in as a robust replacement for your Mercury outboard, matching the original MC#865380A25 specs while delivering enhanced durability for repeated saltwater exposure and heavy use.

Crafted from corrosion-resistant materials, this unit ensures smooth operation season after season. Imagine effortlessly raising your motor for trailering or shallow-water runs without straining the hydraulics— that's the peace of mind it provides.

Key Features That Stand Out

• Precision Engineering: Direct-fit design mirrors OEM tolerances for seamless integration, reducing installation headaches.
• Heavy-Duty Construction: Zinc-plated components and high-pressure seals withstand harsh marine environments, from freshwater lakes to coastal bays.
• Responsive Hydraulics: Fluid dynamics optimized for quick response times, helping you maintain control during sudden maneuvers.
• Extended Service Life: Reinforced rams and pistons handle the rigors of commercial fishing or weekend warrior outings alike.

Unlike generic parts that fail prematurely, this assembly prioritizes longevity without compromising on power output.

Perfect Fit for Popular Mercury Models

Engineered specifically for a wide array of Mercury powerheads, the Sierra 18-6747 slots right into systems originally equipped with MC#865380A25. It's a go-to for owners of mid-range outboards commonly found on bass boats, pontoons, and center consoles. Cross-reference your engine serial number to confirm compatibility, but rest assured it supports models from the late '90s through early 2010s—prime years for reliable performance boating.

Boat owners report swapping it in during routine winterizations, restoring factory-fresh tilt/trim action that transforms handling on the water.

Real-World Benefits for Boaters

Beyond basic functionality, this tilt/trim assembly elevates your entire boating experience:

• Fuel Efficiency Gains: Proper trim adjustment minimizes drag, stretching your tank further on long trips.
• Safer Operation: Instant response prevents bow rise or propeller ventilation in rough seas.
• Cost Savings: Aftermarket quality at a fraction of dealer prices, with no drop in reliability.
• Versatility: Ideal for both recreational cruisers and tournament anglers needing precise depth control.

Many users notice improved planing times right after install, proving its value in competitive scenarios.

Effortless Installation and Pro Tips

Most DIY mechanics complete the swap in under two hours with basic tools: wrenches, a hydraulic jack, and fresh gear oil. Start by relieving system pressure, disconnect lines carefully to avoid spills, and secure the new unit with provided hardware. Pro tip: Flush the entire hydraulic circuit beforehand to eliminate old fluid contaminants that could shorten the new assembly's life.

Always bench-test for leaks post-install before hitting the water— a small step that prevents big headaches.

Troubleshooting Common Tilt/Trim Woes

Slow extension? Leaking fluid? These are classic symptoms signaling it's time for replacement. The Sierra 18-6747 addresses root causes like worn seals and fatigued rams, restoring full up/down range. If your motor "creeps" under load, check motor relays first, but this assembly often resolves interconnected hydraulic issues.

Regular inspections catch problems early: Listen for unusual whining or monitor fluid levels weekly during peak season.

Maintenance for Peak Performance

Keep it running like new with simple habits:

1. Inspect seals quarterly for cracks.
2. Top off with Mercury-compatible hydraulic oil annually.
3. Cycle the system fully 10 times before each outing to distribute fluid evenly.
4. Rinse with freshwater after saltwater runs to combat corrosion.

These routines extend service intervals, keeping you on the water instead of in the shop.

Why Boaters Trust Sierra for Marine Replacements

Sierra's reputation in the aftermarket stems from rigorous testing against OEM benchmarks. Anglers and mechanics alike praise the 18-6747 for its no-fuss reliability, often outlasting originals in demanding conditions. It's not just a part; it's an investment in uninterrupted adventures.

Frequently Asked Questions