Great Modifications for the Yamaha YZ65 - VFORCE4 V4R82B-I

Great Modifications for the Yamaha YZ65 - VFORCE4 V4R82B-I

VForce4 Reed cage Yamaha YZ65Yamaha YZ65 - VFORCE4 V4R82B-I

The MOTO TASSINARI VForce reed system has been a standard for performance in 2-Stroke racing. Let's think about when we think about top performing 2-Strokes motorcycles. For years KTM uses the V-Force Reed system stock on their motorcycles. KTM knows the V-Force system is a top performing reed cage and gives their motorcycles an edge. So why are you not adding one asap, you want the winning edge so use the newest version the V-Force4 V4R82B-I to your Yamaha 2019 YZ65.

Let's read what Moto Tassinari tells us about the reason why the V-Force system outperforms the stand OEM style single reed cage system.

What is the advantage of V-Force over OEM:

"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."


The original Moto Tassinari V-Force reeds offer the advantages over single style reed system. The first thing about the V-force system has double the reed tip surface area over conventional reeds (OEM). The dual reed system will increase power throughout the power band (increase bottom end, pulls harder in the mid-range and increase over rev.) The increases are created by using less reed travel.  The V-Force system increases the air-flow greatly due to the increased reed surface area. With less movement over the conventional reed system allows for less wear. 

New Improved VFORCE4 Features:

  • All-new reed petal resin system, carbon fiber, and lay-up
  • Pre-curved reed petal ensures a better seal at the 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 the cage tip to increase air velocity from outer ports
  • Long reed stops added to progressively slow petal tip velocity, for increased petal durability
  • The reduced frontal area of a central wing by 15.6% combined with a more aerodynamic shape


  • Rubber overmodling on the reed tip surface of the cage to further enhance petal life
  • Pre-curved reed petal ensures a better seal at the tip



  • Custom intake manifold boot that offers a straighter shot to the intake that greatly enhances both airflow and performance
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