Yamaha Replacement Lower Unit | A25F | 4 Stroke | 90-418-A25F

SE418 Replacement Lower Unit for Yamaha® 90° V6 — Counter-Rotation (1.86)

Direct OEM-fit, counter-rotation performance. The SE418 is a complete, fully assembled gearcase engineered to replace Yamaha 90° V6 2-Stroke counter-rotation lower units. Built to factory specifications, it delivers smooth shifting, reliable operation, and long service life.

Highlights

• Direct-fit replacement for most Yamaha 90° V6 2-Stroke outboards with a 1.86 gear ratio
• Counter-rotation only — not for standard rotation applications
• Complete assembly — water pump and all internal components pre-installed
• OEM-level quality — precision-machined gears, shafts, and bearings for dependable performance
• Durable finish — painted black; can be refinished to match your Yamaha outboard
• Reliability tested for consistent performance and long service life

Application

Direct replacement for Yamaha 90° V6 2-Stroke outboards configured for counter-rotation with a 1.86 gear ratio.

Before you order, please verify:

• Engine model and model year
• Rotation (SE418 = counter-rotation)
• Gear ratio (1.86)
• Shaft length

Need help confirming fitment? Contact us for quick application assistance.

Yamaha® is a registered trademark of Yamaha Motor Co., Ltd. Use of the name is for reference only and does not imply affiliation or endorsement.