Kawasaki 400cc/500cc/Yamaha YZFR-3 Lightweight Throttle body Pull/Return Spring

Description

Kawasaki Ninja 400/500 & Yamaha YZF-R3 Lightweight Throttle Body Pull/Return Spring

Engineered, designed, and manufactured in the USA.

This purpose-built torsion spring gives riders a softer throttle pull—approximately 20% less effort—with a more connected, controllable feel. The OEM spring is built for commuting: a stiffer pull and a hard snap-back to guarantee full close. That design leaves little feedback when you roll the throttle, which can be a problem mid-corner and leaned over. This spring is meant to add comfort and confidence without giving up reliable return.

Fitment

• Kawasaki Ninja 400
• Kawasaki Ninja 500
• Yamaha YZF-R3

Why we made our own
Spears Racing looked at several “lightened pull” springs on the market. Inconsistency from unit to unit is why we designed and manufacture our own, engineered to a consistent spec so every customer gets a purpose-built part—not a random lighter coil.

About the spring
Torsion springs store and release rotational energy. When wound in the direction of the coil, body diameter decreases slightly and length increases slightly. The legs can hold a mechanism in position across the centerline. A correctly designed torsion spring returns to its original position after a safe amount of deflection. That ability drops if the spring is overstressed (rotated too far). This part is designed for that application—not as a generic hardware-store substitute.

RACE USE ONLY

Spears Racing has been designing and manufacturing race products for decades, including parts for small “commuter” platforms that riders now use for something they were never intended for: racing. That work produced application-specific, proprietary components that go through research and development before they reach customers.

Bullet highlights 

• Approx. 20% lighter throttle pull
• Improved feel and control, especially mid-corner
• Consistent, purpose-built spec (not a generic lightened OEM)
• Designed and manufactured in the USA
• Fits Ninja 400, Ninja 500, and YZF-R3
• Race use only