YZ-4 Narrow Rear Belt Pulley Kit Compatible with YZ-4 - Z4-309C by Yokomo  [Z4-309C]

Aluminium Narrow Pulley & Belt Solution for YZ-4

The Yokomo Z4-309C narrows the rear belt span on YZ-4 4WD off-road vehicles, cutting friction and reducing the rotational burden on the driveline. The aluminium construction aims to minimize mechanical loss on power-restricted setups rather than increase peak output.

Fitment focuses on the rear belt section. The supplied pulley and belt substitute the stock rear routing parts to tighten the belt path. A basic level of RC mechanical experience is adequate; typical work includes removing the existing rear-belt parts and refitting the new components with attention to correct tracking and tension.

Performance role: by reducing belt resistance, the kit helps reduce drivetrain power draw during use, which benefits stock-class or other limited-power categories. Use it as a fine-tuning component for smoother belt drive performance rather than a horsepower upgrade.

Fit the Z4-309C to reduce belt friction on YZ-4 platforms and follow careful alignment and tension checks to get the intended efficiency improvements.