Yamaha Gear 2 (1.5/1 Ratio) 6T5-4588E-00-00. Overview. The Yamaha Gear 2 (1.5/1 Ratio) 6T5-4588E-00-00 is a genuine original equipment manufacturer component designed to deliver precise motion transfer and optimized gear performance within your Yamaha system. Featuring a 1.5:1 ratio, this gear plays a critical role in balancing torque and speed, ensuring efficient and smooth operation.. Engineered to Yamaha's exact specifications, this gear provides a precise fit and dependable durability. It is