Yamaha Replacement Lower Unit | 25" | 4 Stroke | 90-422-B25F

SE422 Replacement Lower Unit for Yamaha® F250

Direct OEM-fit performance. The SE422 is a purpose-built replacement for Yamaha F250 4-Stroke gearcases. It arrives fully assembled and ready to install, engineered to meet or exceed factory specifications for smooth shifting, dependable operation, and long service life.

Highlights

• Direct-fit replacement for Yamaha F250 4-Stroke lower units
• Dual water intakes supported; also compatible with early side-intake versions
• Water-cooled bearing carrier for added strength and improved thermal control
• Complete assembly — water pump and all internal components pre-installed
• OEM-level engineering — precision-machined gears, shafts, and bearings
• Durable finish — painted black; can be refinished to match your Yamaha

Application

Direct replacement for Yamaha F250 4-Stroke outboard lower units covered by the SE422 series, including both dual water intake models and early side-intake versions.

Before you order, please verify:

• Engine model and model year
• Shaft length (20″/25″/30″ as applicable)
• Gear ratio
• Water intake style (dual vs. side-intake)

Need help confirming fitment? See the fitment guide below or contact us for 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.