SEI SE416 Lower Unit for Yamaha F175 & F200 4-Cylinder 1.86:1 RatioThe SEI SE416 is an aftermarket replacement lower unit for select Yamaha F175 and F200 inline four-cylinder outboards. Featuring a 1.86:1 gear ratio, it is available for 20" and 25" shaft applications. Each unit comes in black and can be painted to match your engine.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 Aftermarket replacement lower unit from SEI Marine; For select Yamaha F175 and F200 inline four-cylinder applications; 1.86:1 gear ratio; Available for 20" and 25" shaft lengths; Black finish that can be painted to match; Shaft Length Selection 20" application: SEI part number 90-416-A20F; 25" application: SEI part number 90-416-A25F; Select the shaft-length designation that matches your engine application.Fitment RequirementsConfirm your full Yamaha engine model number against SEI's application guide before ordering. Verify the engine year, serial number, existing gear ratio, and shaft-length designation. Horsepower alone does not establish compatibility.This listing covers select inline four-cylinder applications. Do not assume compatibility with Yamaha F200 V6 engines or other SE416 configurations.