Complete Gearcase Assembly – Fits Yamaha V6 150-225 HP (Replaces 64K-45300-04-NA, 64K-45300-03-NA)
Complete Gearcase Assembly – Fits Yamaha V6 150-225 HP (Replaces 64K-45300-04-NA, 64K-45300-03-NA) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Complete Gearcase Assembly – Fits Yamaha V6 150-225 HP (Replaces 64...
Product Details
This aftermarket Complete Gearcase Assembly – Fits Yamaha V6 150-225 HP is a direct-fit replacement for Yamaha 2-stroke V6 2.6L (150-225 HP, 1986–2014) and 4-stroke V6 (150 HP, 2004–2018) engines with a 20-inch shaft and 2.0:1 gear ratio.
It serves as a direct interchange for Yamaha part numbers 64K-45300-04-NA and 64K-45300-03-NA, as well as SEI Marine references 90-416-B20 and 90-416-B20F.
- Engineered for a direct bolt-on installation.
- Constructed from marine-grade aluminum for durability in harsh saltwater and freshwater environments.
- Protected by a comprehensive 3-Year No-Fault Warranty for your peace of mind.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number |
|---|---|
| Yamaha | 64K-45300-04-NA |
| Yamaha | 64K-45300-03-NA |
| SEI Marine | 90-416-B20 |
| SEI Marine | 90-416-B20F |
Engine & Model Compatibility
Confirm your engine model/year in the table below. Verifying your engine's model, year, and shaft length is critical for ensuring a proper fit.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | VZ150TLR | 150 | 2-Stroke | 2008–2014 | 64K-45300-04-NA | |
| Yamaha | V150TLR | 150 | 2-Stroke | 2006–2008 | 64K-45300-04-NA | |
| Yamaha | V150TLRD | 150 | 2-Stroke | 2005 | 64K-45300-04-NA | |
| Yamaha | V150TLRC | 150 | 2-Stroke | 2004 | 64K-45300-04-NA | |
| Yamaha | VZ150TLRC | 150 | 2-Stroke | 2004 | 64K-45300-04-NA | |
| Yamaha | VX150TLRC | 150 | 2-Stroke | 2004 | 64K-45300-04-NA | |
| Yamaha | V150TLRB | 150 | 2-Stroke | 2003 | 64K-45300-04-NA | |
| Yamaha | VZ150TLRB | 150 | 2-Stroke | 2003 | 64K-45300-04-NA | |
| Yamaha | VX150TLRB | 150 | 2-Stroke | 2003 | 64K-45300-04-NA | |
| Yamaha | V150TLRA | 150 | 2-Stroke | 2002 | 64K-45300-04-NA | |
| Yamaha | VZ150TLRA | 150 | 2-Stroke | 2002 | 64K-45300-04-NA | |
| Yamaha | VX150TLRA | 150 | 2-Stroke | 2002 | 64K-45300-04-NA | |
| Yamaha | V150TLRZ | 150 | 2-Stroke | 2001 | 64K-45300-04-NA | |
| Yamaha | VZ150TLRZ | 150 | 2-Stroke | 2001 | 64K-45300-04-NA | |
| Yamaha | VX150TLRZ | 150 | 2-Stroke | 2001 | 64K-45300-04-NA | |
| Yamaha | V150TLRY | 150 | 2-Stroke | 2000 | 64K-45300-04-NA | |
| Yamaha | VZ150TLRY | 150 | 2-Stroke | 2000 | 64K-45300-04-NA | |
| Yamaha | VX150TLRY | 150 | 2-Stroke | 2000 | 64K-45300-04-NA | |
| Yamaha | P150TLRX | 150 | 2-Stroke | 1999 | 64K-45300-03-NA | |
| Yamaha | PX150TLRX | 150 | 2-Stroke | 1999 | 64K-45300-03-NA | |
| Yamaha | P150TLRW | 150 | 2-Stroke | 1998 | 64K-45300-03-NA | |
| Yamaha | P150TLRV | 150 | 2-Stroke | 1997 | 64K-45300-03-NA | |
| Yamaha | P150TLRU | 150 | 2-Stroke | 1996 | 64K-45300-03-NA | |
| Yamaha | P150TLRT | 150 | 2-Stroke | 1995 | 64K-45300-03-NA | |
| Yamaha | P150TLRS | 150 | 2-Stroke | 1994 | 64K-45300-03-NA | |
| Yamaha | P150TLRR | 150 | 2-Stroke | 1993 | 64K-45300-03-NA | |
| Yamaha | P150TLRQ | 150 | 2-Stroke | 1992 | 64K-45300-03-NA | |
| Yamaha | P150TLRP | 150 | 2-Stroke | 1991 | 64K-45300-03-NA | |
| Yamaha | PROV150LD | 150 | 2-Stroke | 1990 | 64K-45300-03-NA | |
| Yamaha | PROV150LF | 150 | 2-Stroke | 1989 | 64K-45300-03-NA | |
| Yamaha | PROV150LG | 150 | 2-Stroke | 1988 | 64K-45300-03-NA | |
| Yamaha | PROV150LH | 150 | 2-Stroke | 1987 | 64K-45300-03-NA | |
| Yamaha | PROV150LJ | 150 | 2-Stroke | 1986 | 64K-45300-03-NA | |
| Yamaha | VF150LA | 150 | 4-Stroke | 2013-2018 | 63P-45300-05-8D | |
| Yamaha | F150LB | 150 | 4-Stroke | 2015-2018 | 63P-45300-05-8D | |
| Yamaha | F150LCA | 150 | 4-Stroke | 2017-2018 | 63P-45300-05-8D | |
| Yamaha | F150LA | 150 | 4-Stroke | 2012-2014 | 63P-45300-05-8D | |
| Yamaha | F150TLR | 150 | 4-Stroke | 2006-2011 | 63P-45300-05-8D | |
| Yamaha | F150TLRD | 150 | 4-Stroke | 2005 | 63P-45300-05-8D | |
| Yamaha | F150TLRC | 150 | 4-Stroke | 2004 | 63P-45300-05-8D |
Technical Specs
- Product Type
- Complete Lower Unit/Gearcase Assembly
- Installation
- Direct bolt-on replacement
- Connection
- Standard V6 Yamaha mounting pattern
- Housing Material
- Marine-grade aluminum
- Housing Color
- Black
- Dimensions (L x W x H)
- 78.0 x 23.0 x 118.0
- Weight
- 27.0 kg (59.5 lbs)
- Fitting Type
- Standard 20" driveshaft
- Operating Temperature
- Marine environment
- Gear Ratio
- 2.0:1
- Rotation
- Right-hand
- Warranty
- 3-Year No-Fault Warranty
What’s in the Box
- 1 x Complete Gearcase Assembly (replaces 64K-45300-04-NA / 64K-45300-03-NA)
Installation Notes
- Ensure the engine is off and disconnect the battery terminals for safety.
- Drain the old gear lube completely from the existing gearcase.
- Remove the propeller assembly.
- Unbolt and carefully lower the existing gearcase from the engine's midsection.
- Thoroughly clean the mating surfaces on the engine housing where the new unit will attach.
- Carefully align the new gearcase, ensuring the driveshaft, shift shaft, and water tube are correctly positioned.
- Secure the new gearcase by tightening the mounting bolts to the manufacturer's specified torque pattern and value.
- Reinstall the propeller assembly, ensuring it is properly torqued.
- Fill the gearcase with the recommended marine gear lubricant to the correct level as per the owner's manual.
- Reconnect the battery and test the engine's shifting and operation in a safe environment before open water use.
Troubleshooting & FAQ
How do I confirm this gearcase fits my Yamaha engine?
This unit fits specific Yamaha V6 2-stroke (1986–2014) and 4-stroke (2004–2018) models. Please consult the "Engine & Model Compatibility" table on this page and cross-reference your engine's model number and year. Verifying the 20" shaft length and 2.0:1 gear ratio is also crucial.
What is the gear ratio and rotation of this unit?
This is a standard right-hand rotation gearcase with a 2.0:1 gear ratio, compatible with the specified Yamaha models.
What are common signs that my original gearcase Is failing?
Signs of failure include metallic shavings or milky/cloudy gear lube (indicating water intrusion), excessive vibration, grinding noises when shifting or running, and difficulty shifting into or out of gear.
What maintenance does this gearcase require?
Regular maintenance includes checking and changing the gear lube at intervals recommended by your engine manufacturer (typically annually or every 100 hours). Also, inspect the seals for leaks periodically to ensure long-term performance.
Is this an OEM Yamaha part?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
What are your shipping speed & cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
What is the warranty and return policy?
This product is covered by a 3-Year No-Fault Warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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