Yamaha - Shifter - 6K1-45641-01-00Yamaha Shifter Gear Engagement Component 6K1 45641 01 00 Overview The Yamaha Shifter 6K1 45641 01 00 is one of those parts that makes the difference between smooth gear changes and that clunky, unreliable feel nobody wants on the water. When its working right, shifting into forward or reverse feels clean and solid. When it starts wearing out, youll notice hesitation, grinding, or difficulty staying in gear. Its a key piece in keeping your lower unit