SEI Yamaha V6 2 Stroke 1.81:1 25" Shaft Counter Rotation Replacement Lower UnitNote for purchasing: You must verify your Gear Ratio. Call for application assistance if needed, and have your engine serial number ready when calling. This unit replaces most Yamaha 2 Stroke V6 3.1 & 3.2L (225HP / 250HP) engines with 1.81:1 gear ratio and 25" drive shaft. This model is for counter rotation only. SE428, 1.81:1, 25" Driveshaft; Counter Left Hand Rotation; 76 V6 2 Stroke 3.1L & 3.2LYamaha Outboards; Includes Sterndrive Engineering's No Fault Warranty for 3 Years; Measuring Guide: Use 20" models when from the top of the driveshaft to the mounting surfaces measures 22.5"; Use 25" models when from the top of the driveshaft to the mounting surfaces measures 27.5"; Item is subject to a 20% restocking fee (Boat Covers, Bimini Tops, Outdrives, Drop Ship Items and Special Order Parts)!**Year, Serial Number, and Horsepower are required to order. Please contact us with this information after you place your order otherwise processing will be delayed.