Yamaha Replacement Lower Unit | 2.6L | 25" | 2 Stroke | 90-418-A25

<h2>SE418 Replacement Lower Unit for Yamaha® 90° V6 — Counter-Rotation (1.86)</h2>

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

<h3>Highlights</h3>
<ul>
  <li><strong>Direct-fit replacement</strong> for most Yamaha <strong>90° V6 2-Stroke</strong> outboards with a <strong>1.86 gear ratio</strong></li>
  <li><strong>Counter-rotation only</strong> — not for standard rotation applications</li>
  <li><strong>Complete assembly</strong> — water pump and all internal components pre-installed</li>
  <li><strong>OEM-level quality</strong> — precision-machined gears, shafts, and bearings for dependable performance</li>
  <li><strong>Durable finish</strong> — painted black; can be refinished to match your Yamaha outboard</li>
  <li><strong>Reliability tested</strong> for consistent performance and long service life</li>
</ul>

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  <strong>Compatibility Note:</strong> SE418 is for <em>counter-rotation</em> applications with a <strong>1.86</strong> gear ratio. Do <em>not</em> use for standard rotation.
</div>

<h3>Application</h3>
<p>Direct replacement for Yamaha <strong>90° V6 2-Stroke</strong> outboards configured for <strong>counter-rotation</strong> with a <strong>1.86</strong> gear ratio.</p>

<p><strong>Before you order, please verify:</strong></p>
<ul>
  <li>Engine <strong>model</strong> and <strong>model year</strong></li>
  <li><strong>Rotation</strong> (SE418 = counter-rotation)</li>
  <li><strong>Gear ratio</strong> (1.86)</li>
  <li><strong>Shaft length</strong></li>
</ul>

<p>Need help confirming fitment? <a href="https://marinepartsco.com/pages/contact">Contact us</a> for quick application assistance.</p>

<p style="font-size:0.9em;opacity:0.8;"><em>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.</em></p>