Skip to Main Content
Stores & Services
We have updated our Privacy Policy. Please click here to review the updates. Accept

Looking for something else?

V Force 4 Reed Valve System Yamaha YZ125 2005-2021

Save $16.89 10%
Fast Lane
Ships Free to Cycle Gear Stores!

Ship to an Address:
Please select a to view availability.

Add to Cart Qty

Pick-up in Store:
Cycle Gear Pacheco Check Nearby Stores

The Cycle Gear Difference
  • 30-Day Best Price Guaranteed
  • Free Shipping Over $49
  • No-Hassle Returns View Details

Related Categories

This product is legal in California only for racing vehicles which may never be used, registered or licensed for use upon a highway.

V Force 4 Reed Valve System Yamaha YZ125

The VForce4 is built upon the solid foundation that made the VForce3 reed valve system such a success. While the VForce3 has been continually refined over the years, this is a complete redesign of the entire system. All the components that go into making a VForce reed valve system have been significantly changed since the VForce3. The reed cage design now incorporates an airfoil shape at the reed tip area to increase air velocity from the outer ports. The Vforce4 also uses an all-new reed petal resin system, carbon fiber and lay-up on the pre-curved reed petals. The benefit of the pre-curved reed petal is better sealing at the tip area. The VForce4 also features longer reed stops to progressively slow petal tip velocity, for increased petal durability. The combined reed tip area has been increased by over 10% resulting in increased total airflow. Finally, the Vforce4 features a reduced frontal area of central wing by 15.6% combined with a more aerodynamic shape.


  • Advanced reed petal resin system, carbon fiber and lay-up
  • Pre-curved reed petal ensures better seal at the tip
  • Wider reed cage for maximum airflow
  • Combined reed tip area is increased by 10.5% for better airflow
  • Airfoil shape added to cage tip to increase velocity from the outer ports
  • Long reed stops added to progressively slow reed petal tip velocity for increased petal durability
  • Reduced frontal area of the central wing combined with a more aerodynamic shape
  • Replacement reeds available
  • Made in the USA

Note: Images are for reference only, actual product will vary based on make and model.

Read More

This product is vehicle specific. Click here to select your vehicle to ensure fitment.

This Product Fits:

YZ125 2005-2021

This item is also available for 50 other models:

125 RR 2021
250 RR 2021
300 RR 2021
300 RX 2021
Gas Gas
MC 85 17/14 2021-2023
MC 85 19/16 2021-2023
CR125R 1987-2002
CR80R 1980-2002
CR80RB Expert 1996-2002
CR85R 2003-2007
CR85RB Expert 2003-2007
CR125 2000-2013
CR150 2011
TC125 2016-2022
TC250 2017-2022
TC85 17/14 2014-2023
TC85 19/16 2014-2023
TE150 2017-2019
TE250 2017-2023
TE250i 2018-2023
TE300 2017-2023
TE300i 2019-2023
TE300i Rockstar Edition 2021-2022
WR125 2000-2013
105 SX 2004-2012
125 SX 2016-2022
125 XC 2021-2022
150 SX 2016-2022
150 XC-W 2018-2019
250 EXC 2004-2008
250 SX 2003-2016
250 XC 2017-2019
250 XC-W 2017-2023
250 XC-W TPI 2018-2023
300 EXC 2004-2005
300 MXC 2004-2005
300 XC 2017-2019
300 XC-W 2017-2023
300 XC-W Erzbergrodeo 2023
300 XC-W Six Days 2017-2018
300 XC-W TPI 2018-2023
300 XC-W TPI Erzbergrodeo 2022-2023
300 XC-W TPI Six Days 2019-2020
85 SX (17/14) 2003-2023
85 SX (19/16) 2003-2023
RM85 2002-2023
RM85L 2002-2017
YZ65 2018-2023
YZ85 2023
YZ85 2002-2021
Product Style Item # Store SKU Manufacturer Product # Availability
Product Style V Force 4 Reed Valve System Yamaha YZ125 2005-2021 Item # 1829210 Store SKU Manufacturer Product # V4R04 Availability In Stock: Ships next business day
Join now & get rewarded!

Get free 2-day shipping and 5% cash back on your next order.

Already enrolled in RPM? Link your existing membership here.

We're always looking to get better for our customers. Tell us what you like, what's missing, or what's broken.

Leave Feedback