Uflex Yamaha 90-115hp Zero Torque Feedback Tiller [ZTF TILLER Y1]Yamaha 90 115 Zero Torque Feedback Tiller The four stroke outboard engines are generating high torque loads which can make tiller steered boats difficult to steer. The Uflex ZTF Tiller systems eliminate propeller torque at the tiller handle when the driver is not actively changing direction. Using a hydraulic valve, the propeller torque is locked from reaching the tiller handle unless the driver pushes or pulls on the end of the handle, at which point