Description: General Information for Selecting a SEI 421 or 428 Replacement Gearcase SEI 421/428 gearcases replace many Yamaha 3.1 & 3.2 liter V6 two stroke gearcases from 1990 to present. SEI 421/428 gearcases replace Yamaha 6 cylinder, four stroke 200-225 hp gearcases, 2002 to present. Two stroke = 200 through 250 horsepower Four stroke = 200 through 225 horsepower only. SEI 421 gearcases are standard rotation. SEI 428 gearcases are counter rotation. Available in 20, 25 and 30 transom models. See picture below for help in determining which length you need. Available in 20, 25 and 30 transom models. See picture below for help in determining which length you need. SEI 421/428 gearcases come with a complete water pump installed. Does not include the trim tab. 1.81:1 ratio (16/29 gear teeth) for two strokes. 2:1 ratio (15/30 gear teeth) for four strokes. Shipped without gearlube. Counter Rotation Identification If you have a twin engine boat, you may have a counter rotation unit on the port side. The easiest way is to confirm that is to look at the prop. If the direction of the blades are the same on both props then they are both standard rotation. If the direction of the blades are different then you have a counter rotation on the port side. If you currently have two standard rotation drives you can upgrade the port side to be counter rotating. You will need to get a prop that is opposite rotation. If you are lucky you can buy the exact same prop, only LH rotation. If they do not make it, you will need to buy two new props, one LH and one RH. You don’t want to put two different style props on the boat. 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: 1320 USD
Location: Oldsmar, Florida
End Time: 2024-08-27T12:53:21.000Z
Shipping Cost: N/A 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
Manufacturer Part Number: 90-421-B25F
Country/Region of Manufacture: United States
Brand: Sei Marine Products
UPC: Does Not Apply
SEI Marine Products: 50 pounds
