Boyesen Rad Valve Yamaha YZ85 Your engine is a glutton for air. It will take over 200 "gulps" per second, at velocities of over 500 MPH if your intake valve can handle it. The Boyesen Rad Valve's one-piece, precision casting and continuous aeroform surfaces ensure maximum flow velocities and instant, explosive movement of air particles the moment you crack open the throttle. While other aftermarket valves might change flange sizes or bolt patterns, they still require you to irreversibly cut your intake boot to be properly installed. With the Boyesen Rad Valve, there are no compromises in power, no modifications required, just pure bolt-on power. Features: Redirects intake charge for even distribution to intake ports Constant flow velocity is maintained for instant throttle response and more horsepower One piece design for simple installation Each Boyesen Rad valve is unique and tailor made to fit your model, year and cc displacement Note: Images are for reference only, actual product will vary based on make and model.