Yokomo Z4-309-6 Rear Drive Belt (6mm) for YZ-4  [Z4-309-6]

Reduced-friction 6mm rear belt for YZ-4 setups

The Z4-309-6 is a 6mm width rear drive belt tailored for the Yokomo YZ-4 platform to cut drivetrain load on RC-scale cars that compete in low-power stock categories. Its narrower contact patch compared with wider belts lowers transmission friction without altering the base chassis layout.

From a setup viewpoint, the belt trims drivetrain resistance and sharpens throttle response where motor power is modest. The effect is most notable when used with a narrow aluminium pulley like the Z4-630A, concentrating contact on a smaller diameter and further reducing drag. This arrangement is well suited to circuits prioritising rapid, short bursts rather than sustained top speed.

Installation guidance: check alignment of motor pinion, spur gear and pulleys before final tensioning and avoid excessive tension that increases bearing loads. Inspect pulley grooves and running surfaces for wear and make sure bearings and idlers rotate smoothly after installation. This item is intended for model use only.