Developed on our Dyno and tested extensively on the water, this waterbox features radiused exhaust tubes and end caps for optimum exhaust flow. Unique exhaust baffle will increase the low-end power and mid-range pull of your Kawasaki Watercraft. Delivers up to 15hp on modified engines along with significant torque gains. High-strength aluminum construction will survive backfires and meltdowns. Powder coated to prevent corrosion. A must for modified motors. Includes detailed installation instructions.
2014 & Newer Ultra 310: Eliminates restrictive 2nd waterbox. Requires RIVA Free Flow Exhaust Kit (part# RK16110) and coupler RK15-2.38/3.25.
2011~13 Ultra 300: Direct replacement for original waterbox. Use with stock exhaust outlet hose or RIVA Free Flow Exhaust Kit (part# RK16090-08).
2008~10 Ultra 260/250 models: Replaces restrictive original waterbox. Requires RIVA Free Flow Exhaust Kit (part# RK16090-08).
2007 Ultra 250 models: Eliminates restrictive 2nd waterbox. Requires RIVA Free Flow Exhaust Kit (part# RK16090).
Note: Not designed for use with non-supercharged Ultra LX models.
- Delivers up to 15hp on modified craft.
- Machined hose flanges for reliable coupler retention.
- Radiused exhaust tubes & end caps.
- Powder coated to prevent corrosion.