Original price was: $1,572.25.$1,399.00Current price is: $1,399.00.
“Yamaha 90 Degree Counter Rotation Outboard Lower Unit 150-200 HP – 90-418-B25. Direct replacement for Yamaha 90 Degree V6 2-Stroke outboard engines. High-quality, 100% original and brand new, with a gear ratio of 1.86:1.”
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Manufacturer Warranty: 3-Year
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Return Policy: 60-day, hassle-free returns
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Trusted by 6,000+ boaters across the USA
Upgrade or replace your Yamaha outboard with this high-performance SEI 90-418 Counter Rotation Lower Unit. Designed to fit a wide range of Yamaha 150HP to 200HP outboards (2-Stroke & 4-Stroke), this gear case delivers dependable performance at a fraction of OEM prices.
Key Features:
Direct replacement for Yamaha V6 90° gearcases
Compatible with both 2-Stroke and 4-Stroke Yamaha outboards
Counter Rotation unit – Do not use for standard rotation applications
25″ shaft length – fits most offshore configurations
Pre-filled with high-quality gear lube
Painted black – ready to paint to match your engine
Specifications |
Details |
|---|---|
| Model | SEI 90-418 |
| Rotation | Counter (Left-hand) |
| Shaft Length | 25″ |
| Gear Ratio | 1.86:1 or 2.00:1 (based on engine type) |
| Stroke Compatibility | 2-Stroke & 4-Stroke |
| Warranty | 3-Year |
| Paint | Black (Paintable Surface) |
| Replaces OEM | Yamaha 150–200HP (1990–2024) |
This SE418 Counter Rotation Gear Case replaces Yamaha 2 Stroke V6 2.6 Liter Engines with a 1.86 Gear Ratio and 25″ Drive Shaft.
This SE418 Counter Rotation Gear Case replaces Yamaha FOUR Stroke 150HP Engines with a 2.00 Gear Ratio and 25″ Drive Shaft.
Counter rotation lower unit with short shift shaft.
This SE418 Counter Rotation Gear Case replaces Yamaha 4 Stroke Inline 4 cylinder F175 & F200 Engines with a 1.86 Gear Ratio and 25″ Drive Shaft.
| Weight | 90 lbs |
|---|---|
| Dimensions | 23 × 13 × 31 in |
| Ratio/Motor/Length |
1.86/2-Stroke/25" Shaft ,2.00/4-Stroke/25" Shaft ,2.00/4-Stroke/25" Shaft/ Short Shift Shaft /Counter rotation ,F200/F175 / 4 Cyl. /25" Shaft/ 1.86 4 Stroke |
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Original price was: $1,330.89.$1,199.00Current price is: $1,199.00.
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Original price was: $1,330.89.$1,199.00Current price is: $1,199.00.In stock
Original price was: $1,921.90.$1,699.00Current price is: $1,699.00.
In stock
Original price was: $1,330.89.$1,199.00Current price is: $1,199.00.For further inquiries :
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Paula Burke –
After a flawed Amazon purchase, this unit saved my season. Crisp shifts, tight seals, and stellar service. Finally, a company that cares!
Anthony Jones –
No more jerky shifts. Smooth as silk now!
Shelly Nguyen –
The zinc coating resists corrosion beautifully. After saltwater exposure, the unit looks and performs like new. Shifts are crisp, and the prop spins freely. 10/10!
Carrie Rice –
Perfect for DIYers. Saved $$$ on mechanic fees.
Eric Robinson –
Year-round endurance—no compromises!
Jeremy Marsh –
I’ve tested this unit in saltwater for three weeks, and there’s no sign of corrosion. The gears engage smoothly, and it’s noticeably quieter than my old OEM part. Highly recommend for marine use!
Julian Lucas –
Paired this with a high-performance prop—the combo is unstoppable. The unit handles aggressive acceleration effortlessly, and the oil stays contaminant-free. A must-have for speed enthusiasts!
Rachael Hall –
The zinc-anodized bolts haven’t rusted after weeks in brackish water. Installation was tool-free, and the unit outperforms my old OEM part. A must-buy for saltwater boaters!
Joel Mason –
Had it running in 30 minutes flat. Zero issues so far.
Javier Garza –
Didn’t need YouTube tutorials—manual was crystal clear.
Timothy Smith –
No special tools needed. Done in a coffee break!
Cassandra Mcdaniel –
Eco-conscious design—heavy-duty!
Rachel Kirby –
Installed this during a storm—still took under an hour. Shifts are smooth, runs cool, and no leaks. A reliable upgrade for any condition!