Front disc brake conversion kit for the Kawasaki KFX90 (2007-2026) with the stock single A-arm front end. It replaces the stock front drum brakes with a hydraulic front disc setup: new spindles, 4/110 hubs, discs, calipers, brake lines and a right-hand lever with master cylinder.
BRAKE KIT ONLY: no A-arms, shocks or widening parts are included. The kit mounts to your stock single A-arms.
What's included
- Left and right machined spindles, 0.75 in (19.05 mm)
- Stepped mounting pins with hardware (mount the kit spindles to your stock single A-arms)
- Two front hubs, 4/110 bolt pattern
- Two front brake discs with mounting screws
- Right-hand brake lever with master cylinder
- Two brake lines (106 cm) with calipers and pads
- Rubber hub covers and castle nuts
Hubs and wheels
The kit hubs are 4/110 (4 studs on a 110 mm circle). The stock front bolt pattern on the Kawasaki KFX90 is 4/110, so the stock front wheels should bolt to the kit hubs. Measure across opposite studs before ordering: 110 mm is about 4.33 in.
Tie rod ends
Tie rod ends: the stock tie rod ends are expected to work with this kit. Our tie rod ball joint ends are available if needed; select "Add Tie Rod Ball Joints? Yes" (+$50). Do not drill or enlarge the spindle steering-arm hole on this model. If a tie rod end does not seat, stop and contact us. If any tie rod end does not seat fully without play, do not ride: stop and contact us.
Mounting pins
The kit spindles mount to your stock single A-arms with the included stepped mounting pins. Each mounting pin must seat fully in the stock A-arm with no play. If it does not, do not ride: stop and contact us. Do not drill, grind or cut the mounting pin, the kit spindle or any weld.
Installation and safety
- Installation: remove the stock front brake system, hubs and spindles. The stock front brake lever is cut off and replaced by the kit lever and master cylinder. See the install photos.
- Before you cut anything, check how your rear brake and parking brake are operated. If they share the stock front brake lever or linkage, contact us first.
- An adult or a qualified technician must install this kit. We recommend professional installation if you are not experienced with hydraulic brake systems.
- Fill and bleed the hydraulic system before the first ride. Use only the brake fluid type marked on the master cylinder cap.
- Tighten the castle nuts and fit new cotter pins.
- Before a child rides, an adult tests the front brakes at walking speed.
- Re-check every fastener after the first ride.
- Follow the vehicle manufacturer's age, supervision and safety-gear guidance for this model. This kit does not change those recommendations.
- Aftermarket modification may affect your vehicle's factory warranty.
- Modifications may be necessary to fit this kit to your machine. Contact us before drilling, grinding or cutting any part.
Fits
Kawasaki KFX90, 2007-2026, stock single A-arm front end. Not for the 2003-2006 KFX50 or the KFX80. Questions about fit? Contact us with your year and model before ordering.
All sales subject to Diamond J Customs Terms of Sale – see our store policies.
