SEI SE430 Yamaha LF250/LF300 Counter-Rotation Lower Unit 1.75:1 30" ShaftThe SEI 90-430-B30F SE430 is an aftermarket counter-rotation replacement lower unit for select 20102021 Yamaha LF250 and LF300 outboards. Featuring a 1.75:1 gear ratio and 30-inch driveshaft configuration, it carries OE replacement reference 6CF-45300-16-8D.This item is subject to a 20% restocking fee.Year, serial number, and horsepower are required to process your order. Please contact us with this information after placing your order. Processing will be delayed until this information is received.Features Counter-rotation configuration; 1.75:1 gear ratio; 30-inch driveshaft configuration; Applications and Replacement ReferenceFor compatible Yamaha LF250UCA and LF300UCA applications listed in SEI's application guide. SEI part number: 90-430-B30F; OE replacement reference: 6CF-45300-16-8D; Fitment Restrictions Does not fit engines originally built with two-piece driveshafts.; Does not fit engines equipped with TERE (Thrust Enhancing Reverse Exhaust).; Fitment and OrderingConfirm your full engine model number, serial number, existing gearcase, rotation, gear ratio, shaft length, original driveshaft construction, and TERE status before ordering. Horsepower and year alone do not confirm compatibility.