Vforce Reed Valve - Yamaha

The unique design of the VForce reed valve system features double the reed tip surface over a conventional reed valve design.
 
This has two major benefits: 1) The reed petals only travel half the distance as a conventional reed valve design to get the same airflow. 2) Because the reed petals only need to travel half the distance of that on a conventional reed valve design, there is a greater chance of them being fully opened as well as a better chance of sealing when they are "closed".
 
A reed petal never truly "closes" in a classic sense, as it is always in movement. Consider this, an engine operating at 8,000 RPM results in a reed petal opening and closing 133 times in one second.
 
This fact, sheds light on another VForce advantage. Since the petals are only traveling half the distance, they generally last longer as they receive less wear than the reed petals on a conventional reed valve design.
 
VForce 4Ri utilises a winged air guide that increases air velocity for a dramatic gain in throttle response. Paired with the new winged air guide is a custom intake manifold boot that offers a straighter shot to the intake that greatly enhances both airflow and performance. The VForce4Ri also incorporates carbon fibre reed petals designed to ensure superior reliability and maximum performance.
 
VForce 4R offers enhanced reed petal life as well as all the added benefits of the unique Vforce reed valve design. Vforce 4 reed valves are the world leading design and performance reed valve with gains in power no other reed valve standard or aftermarket can match. With a twin stack system you get twice the tip surface and with petals only needing to travel half the distance of a normal single stack, Vforce4 air/fuel control is massively improved when compared to stock.
 
VForce 3 reed valves are the world leading design and performance reed valve with gains in power no other reed valve standard or aftermarket can match. with a twin stack system you get twice the tip surface and with petals only needing to travel half the distance of a normal single stack, Vforce3 air/fuel control is massively improved when compared to stock
 
VForce 4X for the Yamaha YZ250 and YZ250X motorcycles has been designed to offer you exceptional durability and overcome the shortcomings of the stock reed valve system.