Description: General Information for Selecting a SEI 206 Replacement Gearcase SEI 206 replacement gearcases fit many Mercury and Mariner 2.0, 2.4 and 2.5 liter V6 engines from 1979 to current. SEI 206 gearcases are available in either 2:1 or 1.87:1 gear ratios in Standard Rotation only. SEI 206 units are not available with the optional 2.3:1 high altitude gear set. 25” transom models 1988 and older use a five inch spacer between a standard 20” midsection and the lower unit. Longer mounting studs were installed into these gearcases. SEI 206 units do not come with the longer studs and are not available from SEI. The old studs must be reused or new ones sourced from elsewhere. 20” and 25” transom models are available. See the picture below to help determine which length you need. The SEI 206 units use anodes located above the cavitation plate. They are available separately. SEI part number is 90-206-05K. SEI 206 Replacement for Mercury 2.0, 2.4 and 2.5 Liter V6 Engines Gear Ratio Gear Count Engine Length Bullet Diameter SEI Part Number 1.87:1 15/28 20” 4 ¾” 90-206-A20 1.87:1 15/28 25” 4 ¾” 90-206-A25 2:1 14/28 20” 4 ¾” 90-206-B20 2:1 14/28 25” 4 ¾” 90-206-B20 1.78:1 14/25 20” 4 ¼” N/A* * SEI 206 series units can be used in place of this unit. We recommend 2:1 for 150 HP and smaller horsepower engines. For 175HP and up, use the 1.87. The customer will need to purchase a new propeller for a 4 ¾” case. The propeller pitch may need to be changed. If you are not sure whether you are replacing a unit on a 2.0,2.4 or 2.5 liter V6 (SEI 206) or a 3.0 liter V6 (SEI 216), the easiest way to tell the difference is by the material that the water pump is made out off. See the picture below for help in determining what type of Mercury V6 gearcase you are replacing. Any reference to Original Equipment Manufacturer (OEM) names, trade names, specifications, or part numbers is for informational purposes only. Sterndrive Engineering Inc. is not affiliated with any of the OEMs referred to in this ad. Copyrights and Trademarks belong to their respective companies.Copyright 2018 Sterndrive Engineering Inc. All Rights Reserved. Powered by SixBit's eCommerce Solution
Price: 1299 USD
Location: Oldsmar, Florida
End Time: 2023-09-02T20:13:04.000Z
Shipping Cost: 50 USD
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Item Specifics
Return shipping will be paid by: Buyer
Returns Accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money Back
Return policy details:
Brand: Sei Marine Products
Manufacturer Part Number: 90-206-B20
UPC: Does Not Apply
