V-Force (VF4) Yamaha YFZ350 Banshee 88-07
Application: Yamaha Banshee
Model Years: All
Application: Yamaha RD250, RD350 and RD400 (see note below)
Model Years: All
Yamaha RD250, 350 & 400 owners please note: Installing these reed valves will require modification of the intake port of the cylinders. While the bolt pattern is the same, the valve will not just slide in. Material removal on the intake port walls will be required. If you do not have the ability to carry out the modifications please do not purchase the valves.
The reed valve system V-FORCE4 has been developed on the solid base of V-FORCE3, to which many enhancements have been made. The carbon fibre reed petals combined with the new resin frame boost the velocity of your machine, thanks to an airflow 10% better than the first fit. The V-FORCE4 arosystem is fitted with external walls covering and protecting the reed petals and prolonging their longevity.
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
- Screw free design enables super quick reed petal changes
NEW AND IMPROVED VFORCE4 FEATURES:
- All-new reed petal resin system, carbon fibre and lay-up
- Pre-curved reed petal ensures better seal at tip
- Wider reed cage for maximum airflow
- Combined reed tip area increased by 10.5% resulting in increased total air flow
- Airfoil shape added to cage tip to increase air velocity from outer ports
- Long reed stops added to progressively slow petal tip velocity, for increased petal durability
- Reduced frontal area of central wing by 15.6% combined with a more aerodynamic shape
WHAT'S INCLUDED WHEN I PURCHASE THE VFORCE4 REED VALVE SYSTEM?
Moto Tassinari product line brochure, Moto Tassinari and VForce decals, detailed installation instructions, complete VForce4 reed valve system (including two reed valves with reed petals) and gaskets.
The all-new VForce4 is built upon the solid foundation that has made the VForce3 such a success for the last 10 years. While the VForce3 has been continually refined over the years, this is a complete redesign of the entire system. We jokingly say, "The only thing we didn't change is the bolt pattern." However this is actually quite true. All the components that go into making a VForce reed valve system have been significantly changed since the VForce3.
