The new YZ85 VForce4Ri utilizes 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 fiber reed petals designed to ensure superior reliability and maximum performance.
All “R” models include a rubber overmolded pad on the reed tip area of the reed cage to significantly improve reed petal life.
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.
STANDARD VFORCE REED VALVE FEATURES
Double the reed tip surface over a conventional reed valve design
Increased bottom end, stronger mid-range and longer top-end
Greater efficiency due to reduced reed petal travel
More airflow means more horsepower
Reduced reed petal wear
Screw free design eliminates risk of screws going through motor