EPI Economy Clutch Spring Kit - Kawasaki Mule Pro FX/FXT/FXR (2021-2023)
Updated June 15, 2026
The EPI Economy Clutch Spring Kit (part WE437770) is a replacement spring set for the continuously variable transmission (CVT) clutch on select Kawasaki Mule Pro side-by-sides. Designed for general trail riding, this spring-only kit (no clutch weights included) improves belt grip, reduces belt slip and clutch heat, and eliminates the engine braking system (EBS) for a more performance-oriented driving experience. It is compatible with any tire size and all elevations.
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How It Works
In a CVT clutch, springs control the engagement and shift characteristics of the drive and driven pulleys. This kit replaces the factory springs with heavier-duty or differently rated springs that alter the clutch's engagement RPM and shift pattern. By removing the EBS function, the kit allows the vehicle to coast more freely, reducing driveline drag and improving throttle response. The result is crisper acceleration, better belt grip, and reduced clutch heat buildup during trail riding.
Common Failure Symptoms
Over time, factory clutch springs can weaken, leading to poor belt grip, excessive belt slip, delayed engagement, and increased clutch heat. Symptoms include sluggish acceleration, a “surging” feel at low speeds, unusual belt noise, and a noticeable loss of engine braking. This kit addresses those issues by restoring proper spring tension and eliminating the EBS, which can also cause premature belt wear when malfunctioning.
Installation Notes
Installation requires basic mechanical skills and a clutch compression tool (such as EPI CCT510, not included). The kit contains only springs; the stock clutch weights are reused. Ensure the CVT is clean and inspect the belt and sheaves for wear before reassembly. Torque all fasteners to manufacturer specifications. This kit is designed for 2021–2023 Kawasaki Mule Pro FX, FXR, and FXT models (KAF820 chassis).
