SE416 Yamaha V6 2-Stroke 90° Lower Unit - 2.0:1 Ratio, 20" Shaft (Replaces 64K-45300-04-NA)
SE416 Yamaha V6 2-Stroke 90° Lower Unit - 2.0:1 Ratio, 20" Shaft (Replaces 64K-45300-04-NA) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
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SE416 Yamaha V6 2-Stroke 90° Lower Unit - 2.0:1 Ratio, 20" Sha...
SE416 Yamaha V6 2-Stroke 90° Lower Unit - 2.0:1 Ratio, 20" Shaft (Replaces 64K-45300-04-NA) is backordered and will ship as soon as it is back in stock.
Product Details
This is a complete aftermarket SE416 Yamaha V6 2-Stroke 90° Lower Unit, engineered as a direct replacement for Yamaha's 90° V6 2.6L two-stroke outboard engines. It is specifically designed for 150-200 HP models manufactured between 1986 and 2014 that require a 20-inch standard driveshaft and a 2.0:1 gear ratio.
This assembly serves as a direct interchange for Yamaha OEM part numbers 64K-45300-04-NA, 64K-45300-03-NA, 64K-45300-02-NA, and 64K-45300-01-NA, as well as SEI Marine's 90-416-B20.
- Engineered for direct bolt-on installation with no modifications required.
- Manufactured in an ISO 9002 certified facility for quality assurance.
- Protected by an industry-leading 3-year "No-Fault" warranty.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 64K-45300-04-NA |
| Yamaha | 64K-45300-03-NA |
| Yamaha | 64K-45300-02-NA |
| Yamaha | 64K-45300-01-NA |
| SEI Marine | 90-416-B20 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This lower unit is compatible with a wide range of Yamaha V6 2-stroke models. Verify your full model number (e.g., VZ150TLR) to ensure correct fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | VZ150TLR | 150 | 2-Stroke | 2006–2014 | 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 | VZ150TLRD | 150 | 2-Stroke | 2005 | 64K-45300-04-NA |
| Yamaha | V150TLRC | 150 | 2-Stroke | 2004 | 64K-45300-04-NA |
| Yamaha | VX150TLRC | 150 | 2-Stroke | 2004 | 64K-45300-04-NA |
| Yamaha | VZ150TLRC | 150 | 2-Stroke | 2004 | 64K-45300-04-NA |
| Yamaha | V150TLRB | 150 | 2-Stroke | 2003 | 64K-45300-04-NA |
| Yamaha | VX150TLRB | 150 | 2-Stroke | 2003 | 64K-45300-04-NA |
| Yamaha | VZ150TLRB | 150 | 2-Stroke | 2003 | 64K-45300-04-NA |
| Yamaha | V150TLRA | 150 | 2-Stroke | 2002 | 64K-45300-03-NA |
| Yamaha | VZ150TLRA | 150 | 2-Stroke | 2002 | 64K-45300-03-NA |
| Yamaha | VX150TLRA | 150 | 2-Stroke | 2002 | 64K-45300-03-NA |
| Yamaha | VX150TLRZ | 150 | 2-Stroke | 2001 | 64K-45300-03-NA |
| Yamaha | VZ150TLRZ | 150 | 2-Stroke | 2001 | 64K-45300-03-NA |
| Yamaha | V150TLRZ | 150 | 2-Stroke | 2001 | 64K-45300-03-NA |
| Yamaha | V150TLRY | 150 | 2-Stroke | 2000 | 64K-45300-03-NA |
| Yamaha | VX150TLRY | 150 | 2-Stroke | 2000 | 64K-45300-03-NA |
| Yamaha | VZ150TLRY | 150 | 2-Stroke | 2000 | 64K-45300-03-NA |
| Yamaha | P150TLRX | 150 | 2-Stroke | 1999 | 64K-45300-02-NA |
| Yamaha | PX150TLRX | 150 | 2-Stroke | 1999 | 64K-45300-02-NA |
| Yamaha | P150TLRW | 150 | 2-Stroke | 1998 | 64K-45300-02-NA |
| Yamaha | P150TLRV | 150 | 2-Stroke | 1997 | 64K-45300-02-NA |
| Yamaha | P150TLRU | 150 | 2-Stroke | 1996 | 64K-45300-02-NA |
| Yamaha | P150TLRT | 150 | 2-Stroke | 1995 | 64K-45300-01-NA |
| Yamaha | P150TLRS | 150 | 2-Stroke | 1994 | 64K-45300-01-NA |
| Yamaha | P150TLRR | 150 | 2-Stroke | 1993 | 64K-45300-01-NA |
| Yamaha | P150TLRQ | 150 | 2-Stroke | 1992 | 64K-45300-01-NA |
| Yamaha | P150TLRP | 150 | 2-Stroke | 1991 | 64K-45300-01-NA |
| Yamaha | PROV150LD | 150 | 2-Stroke | 1990 | 64K-45300-01-NA |
| Yamaha | PROV150LF | 150 | 2-Stroke | 1989 | 64K-45300-01-NA |
| Yamaha | PROV150LG | 150 | 2-Stroke | 1988 | 64K-45300-01-NA |
| Yamaha | PROV150LH | 150 | 2-Stroke | 1987 | 64K-45300-01-NA |
| Yamaha | PROV150LJ | 150 | 2-Stroke | 1986 | 64K-45300-01-NA |
Technical Specs
- Product Type
- Complete Lower Unit / Gearcase
- Installation
- Direct bolt-on replacement
- Manufacturer
- SEI Marine Products (aftermarket)
- OEM Brand
- Yamaha
- Gear Ratio
- 2.0:1
- Driveshaft Length
- 20" (508 mm)
- Propeller Rotation
- Right Hand (RH)
- Housing Material
- Marine-grade aluminum
- Housing Color
- Black
- Product Dimensions
- 78.0" L x 23.0" W x 118.0" H
- Product Weight
- 27.00 lbs (12.25 kg)
- Warranty
- 3 Years "No-Fault"
What’s in the Box
- 1 x Complete Lower Unit Assembly (Replaces 64K-45300-04-NA)
Installation Notes
For a complete and reliable installation, we strongly recommend purchasing the following items, which are sold separately: the SE405/416 Installation Kit (part #90-416-03K), SE405/406/418 Water Pump Kit (part #96-416-01AK), SE416 Anode Kit (part #90-416-05K), and a Gear Lube and Pump Kit (part #88-102-01K).
- Disconnect the battery and shift the engine into a neutral gear.
- Place a drain pan under the lower unit and remove both the lower drain screw and upper vent screw to empty the old gear lube.
- Remove the bolts securing the lower unit to the engine's midsection frame.
- Carefully lower the gearcase from the engine, ensuring the driveshaft and copper shift shaft disengage without binding.
- Thoroughly clean the mating surfaces on the engine housing. It is highly recommended to install a new water pump kit at this stage.
- Apply a light coat of marine-grade grease to the driveshaft splines and shift shaft.
- Raise the new lower unit into position, carefully aligning the driveshaft, water tube, and shift shaft. Do not force it.
- Secure the unit by installing and tightening the mounting bolts to the manufacturer's specified torque sequence and values.
- Refill the gearcase with high-quality 80W-90 marine gear lube until it flows from the upper vent hole, then install and tighten both screws.
Troubleshooting & FAQ
How do I confirm this lower unit fits my Yamaha engine?
The most reliable method is to match your engine's complete model number and year against our compatibility chart. For example, 'V150TLRD' corresponds to the year 2005. Also, verify your engine's driveshaft length is 20" and the gear ratio is 2.0:1 to ensure an exact match.
What are common signs that my lower unit is failing?
Look for milky or metallic-flecked gear lube (indicating water intrusion or gear wear), excessive vibration, clunking noises when shifting or running, or visible damage to the housing, skeg, or propeller shaft. Any of these symptoms warrant an immediate inspection.
Is a new water pump included or required?
A water pump is not pre-installed. We strongly recommend installing a new water pump kit (our part #96-416-01AK) whenever you replace the lower unit to ensure proper engine cooling and prevent damage from overheating.
What maintenance is required for this gearcase?
Regular maintenance is crucial. Change the gear lube after the first 10-20 hours of break-in, and then every 100 hours or at least once a year. Also, regularly inspect and replace the anode to protect the gearcase from galvanic corrosion.
What gear lube should I use?
Use a high-quality SAE 80W-90 marine gear lubricant that meets API GL-5 standards. Do not use automotive gear oil, as it lacks the necessary emulsifiers and corrosion inhibitors for a marine environment.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility and batch-inspected for consistency and quality.
Shipping speed & cost?
We ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free to most regions, and expedited options will appear at checkout if available for your location.
Warranty & returns?
This part is covered by a 3-year "No-Fault" warranty. If issues arise, contact our support team with your order details. Returns are accepted within our standard window for unused items in original condition. See our full policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement component, not an Original Equipment Manufacturer (OEM) part.
- Professional installation is strongly recommended for safety, proper function, and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for demanding real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with an average transit time of 5–15 days.
- Manufacturer-Direct Value — Our model provides fair, direct pricing without ever compromising on materials or quality control.
Payment & Security
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