Yamaha 20" Lower Unit | OEM 4-Stroke Gearcase | Fits 1999–2014 Yamaha 75 80 90 100 HP Outboards | 1-Year Warranty

Product Overview

Replace your worn or damaged gearcase with this genuine OEM Yamaha 20-inch Lower Unit, designed for 1999–2014 Yamaha 75, 80, 90, and 100 HP 4-stroke outboards. Professionally inspected, serviced, and pressure tested, this lower unit is built to deliver dependable performance and long service life. Each unit is completely disassembled and inspected under magnification. Good OEM gears are retained, while worn components are replaced as needed. The lower unit is then fully resealed, pressure tested to 12 PSI, fitted with a new water pump impeller, and stripped and primed for paint. Backed by a 1-Year Working Warranty, this lower unit is ready for installation after adding the appropriate gear oil.

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Key Features

• Genuine OEM Yamaha 20" lower unit
• Fits Yamaha 75, 80, 90 & 100 HP 4-stroke outboards
• Compatible with 1999–2014 models
• Fully disassembled and professionally inspected
• OEM gears retained if within factory specifications
• Fully resealed
• Pressure tested to 12 PSI
• New water pump impeller installed
• Stripped, primed, and ready for paint
• Ready for installation
• Backed by a 1-Year Working Warranty

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Technical Specifications

Specification	Details
Brand	Yamaha
Product Type	Complete Lower Unit
Condition	Used – Professionally Serviced
Engine Type	4-Stroke
Horsepower	75 HP / 80 HP / 90 HP / 100 HP
Model Years	1999–2014
Shaft Length	20" (Long Shaft)
Driveshaft Length	20-3/4"
Driveshaft Splines	18
Prop Shaft Splines	15
Pressure Test	12 PSI
Water Pump	New Impeller Installed
Finish	Stripped & Primed
Gear Oil	Not Included
Warranty	1-Year Working Warranty

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Inspection & Service Performed

Every lower unit undergoes a complete inspection and service process, including:

• Opened and inspected under magnification
• Fully resealed
• Pressure tested to 12 PSI
• New water pump impeller installed
• Internal gears inspected and serviced
• Stripped and primed for refinishing
• Ready for installation

Important: Gear oil is not included and must be added before operating the lower unit.

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Compatible Applications

Fits select Yamaha 4-stroke outboards including:

Model Years

• 1999
• 2000
• 2001
• 2002
• 2003
• 2004
• 2005
• 2006
• 2007
• 2008
• 2009
• 2010
• 2011
• 2012
• 2013
• 2014

Horsepower

• Yamaha 75 HP
• Yamaha 80 HP
• Yamaha 90 HP
• Yamaha 100 HP

Shaft Length

• 20" Long Shaft

Always verify compatibility using your engine model and serial number before ordering.

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Condition

This OEM Yamaha lower unit has been professionally serviced and is in excellent working condition. Condition highlights include:

• Used OEM Yamaha gearcase
• Fully inspected and serviced
• Fully resealed
• Pressure tested to 12 PSI
• New water pump impeller installed
• Internal gears inspected
• Stripped and primed for paint
• Ready to install
• Minor cosmetic signs of previous use may be present

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What's Included

Your purchase includes:

• Complete OEM Yamaha 20" Lower Unit
• New water pump impeller installed
• Professionally serviced gearcase

Not Included:

• Gear oil
• Propeller
• Mounting hardware unless shown

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Warranty

This lower unit is backed by a 1-Year Working Warranty from Southcentral Outboards. If the unit fails during normal recreational use within the warranty period, it will be repaired or replaced. If a replacement is unavailable, an appropriate resolution will be provided.

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Shipping Information

Every lower unit is professionally packaged to prevent shipping damage. Shipping is available throughout the United States, with international shipping available upon request. For an accurate freight quote, please provide:

• ZIP or Postal Code
• Country
• Residential or Commercial Address
• Liftgate requirement (if applicable)

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Why Buy from EZ Boats Marine?

• Genuine OEM Yamaha Parts
• Professionally Inspected & Serviced
• Fully Resealed
• Pressure Tested
• New Water Pump Impeller Installed
• Fast & Secure Shipping
• Expert Technical Support
• 1-Year Working Warranty

EZ Boats Marine is committed to supplying premium-quality OEM marine parts backed by dependable customer service and technical expertise.

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Frequently Asked Questions

Is this an OEM Yamaha lower unit?

Yes. This is a genuine OEM Yamaha lower unit that has been professionally serviced and tested.

Which engines does it fit?

It fits select 1999–2014 Yamaha 75, 80, 90, and 100 HP 4-stroke outboards with a 20-inch shaft. Always verify compatibility using your engine's model and serial number.

What service has been completed?

The lower unit has been:

• Fully disassembled and inspected
• Resealed
• Pressure tested to 12 PSI
• Fitted with a new water pump impeller
• Stripped and primed for paint
• Inspected to ensure OEM gears meet specifications

Is gear oil included?

No. Gear oil is not included and must be added before use.

Is it ready to install?

Yes. After filling with the recommended gear oil, it is ready for installation on a compatible Yamaha outboard.

Does it include a warranty?

Yes. It includes a 1-Year Working Warranty covering failures during normal use.

Can EZ Boats Marine verify fitment?

Absolutely. Send us your Yamaha engine's model number and serial number, and we'll verify whether this OEM 20-inch Lower Unit for Yamaha 75–100 HP 4-stroke outboards is the correct replacement before you purchase.