Measure outboard shaft length from top of transom to bottom of anti-ventilation plate

To measure outboard shaft length, place the engine on a flat surface with the anti-ventilation plate facing up. Measure from the top of the mounting surface to the bottom of the anti-ventilation plate. This measurement determines the correct shaft length for your boat's transom height.

Common Outboard Shaft Lengths

• Short shaft: 15 inches
• Long shaft: 20 inches
• Extra-long shaft: 25 inches
• Ultra-long shaft: 30 inches

Measuring Your Transom Height

1. Measure from the top of the transom to the bottom where the boat meets the water
2. Add 5 inches for engine tilt clearance
3. Match this total to the closest shaft length

Shaft Length Selection Guide

Key Measurement Points

• Anti-ventilation plate: Must sit at or slightly above boat bottom
• Transom mounting: Engine must clear transom at full tilt
• Propeller depth: Should remain submerged during operation