Hihitomorrow Trim Cap Seal Kit for Yamaha & Suzuki 115–300HP — Aluminium Cap, Marine Seals

Hihitomorrow's Trim Cap Seal Kit is a direct-replacement trim cylinder cap with seals and O-ring engineered to restore hydraulic trim function on select Yamaha and Suzuki outboards.

This kit includes a corrosion-resistant aluminum cap plus precision-molded rubber seals and an O-ring designed to match OEM fitment for many Yamaha and Suzuki engines from mid-2000s to recent models. It’s intended as a service part for the hydraulic trim cylinder, helping stop leaks and maintain proper trim operation when installed according to manufacturer guidelines.

Which engines and model years does this cap seal kit work with?

The kit is cross-referenced to common Yamaha and Suzuki OEM numbers and covers multiple engine families. Check your engine’s parts manual or compare the OEM numbers to ensure compatibility before ordering.

• Compatible Suzuki 4-cylinder 4-stroke: 115HP (2017+), 140HP (2002–2013, 2017+), 150HP/175HP (2006+), 200HP (2015+).
• Compatible Suzuki 6-cylinder 4-stroke: 200HP/250HP (2004–2011), 300HP (2016–2017).
• Compatible Yamaha 4-cylinder and 6-cylinder 4-stroke variants spanning 115–300HP across listed bore and model years.
• Replaces Suzuki OEMs: 48630-96J01/96J02/96J03/96J04 and Yamaha OEMs: 64E-43821-01-00 through -05-00.

How does this kit resist corrosion and wear in a marine environment?

The cap is manufactured from aluminum alloy treated for anti-rust and anti-corrosion performance, while the seals are made from durable rubber compounds selected for saltwater resistance. Together they provide a robust barrier against moisture intrusion when installed correctly.

• Aluminum alloy cap with anti-corrosion surface treatment.
• Precision rubber seals and O-ring formulated for marine use.
• Assembly minimizes galvanic exposure when fitted with compatible fasteners and lubricants.

What’s included in the kit and is it an OEM match?

The kit ships with the aluminum trim cap, the internal seals and a replacement O-ring so you have the essential wear parts for a trim cylinder cap service. It’s offered as a direct-fit replacement that corresponds to specific OEM numbers from Yamaha and Suzuki, making it suitable for routine maintenance or repair.

• One aluminum trim cylinder cap.
• Set of molded rubber seals sized for the cap bore.
• Replacement O-ring for the cap seating surface.
• Cross-reference to Yamaha and Suzuki OEM part numbers for fit verification.

Can I install this kit myself and what tools or tips help ensure a proper seal?

Basic mechanical skill and standard hand tools are sufficient for many home installations, but follow torque specs and service manual steps for your outboard. Clean mating surfaces, inspect the cylinder bore for scoring, and lightly lubricate seals to ease installation and prevent pinching.

• Recommended: service manual, torque wrench, suitable marine grease, clean rags.
• Inspect cylinder bore for damage—replace cylinder components if scored.
• Tighten to OEM torque and cycle trim to seat seals before final checks.

Who is this for: Boaters, marine technicians, and DIY mechanics who need a cost-effective, OEM-referenced replacement for a worn or leaking trim cylinder cap on compatible Yamaha and Suzuki outboards. If you maintain engines in the 115–300HP range and require a corrosion-resistant cap with fresh seals and an O-ring, this kit is intended to help restore trim reliability as part of routine hydraulic maintenance.