Understanding How VForce Reeds Work

How-To Guides & Tutorials  |  12 August 2020

Understanding How VForce Reeds Work main image

If you've ever looked closely at a race-spec two-stroke motocross bike, then you may have noticed a little part with the recognisable VForce logo - this is a reed valve system designed by the smart minds at Moto Tassinari.

What are VForce reeds? 
VForce reed valve systems are the benchmark for aftermarket reed blocks on two-stroke dirt bikes that are designed to enhance engine performance and increase throttle response, which is why they’ve become a staple amongst every serious two-stroke racer.

How do VForce reeds work? 
VForce reeds work in two key ways. 

The first is that the reed petals achieve the same airflow as standard, despite only moving half the distance. The second aspect is that because the reed petals only move half the distance compared a traditional reed valve system, there’s a stronger chance of them being fully opened as well as a better chance of sealing when they’re ‘closed’. 

A reed petal never really closes as it’s always in movement - if an engine is operating at 8000rpm, a reed petal will open and close 133 times in one second. This is where another VForce advantage comes into play - since the petals are only travelling half the distance, they generally last longer as they receive less wear than the reed petals on a conventional reed valve design.

What are the benefits of VForce reeds?
A VForce reed valve system provides a boost in bottom end power, along with stronger mid-range and longer top-end power, while it also allows more airflow which ultimately means more horsepower. The VForce system also uses a completely screw-free design, which prevents a worst-case scenario of one loosening and causing catastrophic engine damage.

What's the difference between VForce3 and VForce4? 
The VForce3 is the original reed valve system that soared to popularity amongst mini riders and two-stroke enthusiasts, and the VForce4 is built on the foundation and success of its predecessor. 

The VForce4 is this is a complete redesign of the entire system - in fact, the only thing that isn’t different between the two models is the bolt pattern. All of the components that went into the VForce3 model have been drastically changed for the latest VForce4.

The VForce4 reed cage design boasts an airfoil shape at the reed tip area to boost air velocity from the outer ports - it uses a reed petal resin system, carbon fibre and lay-up on updated pre-curved reed petals. The benefit of the pre-curved reed petal is better sealing at the tip area. 

The VForce4 boasts longer reed stops to progressively slow petal tip velocity for increased durability, while the combined reed tip area has been increased by over 10 percent for an increase in total airflow. 

The all-new VForce4R models incorporate a rubber over molding on the reed surface to improve reed petal life while also creating a superior sealing surface, as the all-new VForce4Ri models include a custom intake manifold boot that offers a straighter shot to the intake that greatly enhances both airflow and performance.

Comments (9)

Best reeds I need

How do I pick the correct reeds for my 2019 artic cat XF cross country 800? Also will I need an ecu tune afterwards?

Jon bonadona on 25 September 2023
Hey mate, unfortunately snow mobiles are outside of our area of expertise and we would hate to recommend the wrong information! We would recommend reaching out to your local maintenance shop for some advice on this one :)
MXstore Response

Yamaha DT230 Lanza reed

Hello. I need help. I have an enduro with a Yamaha DT230 Lanza engine. I would like to upgrade the factory reed to V-Forcev4. I browsed a lot, but I couldn't find anything specific for this type. While browsing, I found that the following engines basically have the same reeds as the DT230 Lanza. So: Yamaha YZ125 85-87' Yamaha IT200 85-86' Yamaha WR200 92-94' Honda RS125 85-03' Husqvarna CR125 00-13' Husqvarna WRE125 94-13' In principle, the V-Force V4R01H cane fits into these. But what about the DT230 Lanza? I would like them to look into it, because V-Force reeds are not cheap, and you can't even get them in my country, so I have to get them from abroad, so I don't want to buy mismatched reeds. Thanks, Peter (Slovak Republic)

Peter on 13 February 2023
Unfortunately our suppliers aren't able to confirm this fitment and have advised you to reach out to Yamaha to confirm which Reeds will fit your Yamaha DT230 Lanza! Once this has been confirmed we will be able to see if we can order them in for you!
MXstore Response

V force reeds

Hello, I own a yz85 with vforce 3 reeds installed and my friend is now looking for a set of reeds for his kx85 after riding my bike. He has asked me if he should go with vforce 3 or 4 reeds. I was just wondering what the difference between the 3 and the 4 is in terms of performance. (For example, one is better mid range and one is better top end ect.)

Jamison on 16 November 2022
The Moto Tassinari VForce 4R reed valve system has an all-new manifold, reed cage and air-guide system, making it completely different from the VForce 3. The VForce 4 helps most bikes with the initial throttle response making it feel crisper, but the biggest difference is makes is in the midrange. Each bike will vary however, both are an epic upgrade for any 2 stroke!
MXstore Response

V force 3 or 4

Hey looking for a v force for my 2004 300exc ktm. Seem to be reeds for 2003 and lower and 2005 and higher. Any help please

Robbie on 7 February 2022
Hey Robbie, Thanks for getting in touch! We are more than happy to look into this for you, first we will need to know if you are after the Reed Valve Kit or the Reed Petal Kit? Please send us an email to enquiries@mxstore.com.au and we can look into this for you right away! Kindest Regards, MXstore
MXstore Response


I have a yz85 and it has a stock reed in it and I was wondering what differences are between vforce 3and4 are

Jordan on 16 December 2021
Hi Jordan, Thank you for getting in touch! To help answer your question, I have been in touch with our Australian Suppliers to ensure you have all of the correct information: "The VForce4 has had a complete redesign of the system and all components that go into making the VForce have been significantly changed since the VForce3. The reed cage design now incorporates an airfoil shape to increase air velocity from the outer ports. They have used an all-new reed petal resin system, carbon fibre and lay-up on the new pre-curved reed petals. The pre-curve has better sealing at the tip and the new longer reed stops allow for better tip durability. The combined reed tip area has been increased by over 10% resulting in increased total airflow and the frontal area of the central wing has also been reduced by 15.6% combined with a more aerodynamic shape." Hope this helps legend! Wishing you all the best :) Cheers, MXstore
MXstore Response


I have just brought a 2014 YZ250 that already has the force 3 reeds on her.. running 50:1 should i change anything?

Daniel on 6 December 2021
Hi Daniel, Thanks for getting in touch! We are stoked to hear about your new ride. :) 50:1 seems a little lean but that depends on your jetting and what oil you were mixing with. We would suggest if you have VForce reeds installed, it would be ideal to be paired with a complete exhaust system and once installed getting the bike correctly jetted to suit both the reeds and the exhaust. If you have any questions or would like to chat with our team, please feel free to give our Customer Service legends a call. All the best! Kindest Regards, MXstore
MXstore Response

1999 cr125r modified

Just a question, Will V force4 work in my modified engine? If it does how do get one? Thanks

RUBEN TARCA on 21 November 2021
Hey Ruben, We can definitely look into this for you but we will need some further information. If you could please shoot us an email at enquiries@mxstore.com.au we will be able to reach out to our suppliers for you!
MXstore Response

Vforce 3 or 4

Evening, I race an RS 250 Honda Nf5 1989 model and I'm very interested in fitting a couple of V force reed cages on for improved performance. I know there is an early Honda CR 125 that has an identical 4 bolt rectangular reed cage I'm just not sure which one it is. Is there any way of checking before I buy? Thank you in advance Martin Greenwood

Martin Greenwood on 24 July 2021
Hi Martin, Thank you for getting in touch! I have just created enquiry #603714 with our team so that we can look into this further and see what we can do to help! If you have any further questions, please do not hesitate to reach out but otherwise, our team will be in touch soon. :) All the best legend! Cheers, MXstore
MXstore Response

v force reeds

i own a 1974 yamaha mx 250 do v force make reeds for this or do you know where i could get an aftermarket reed to suit..

norm collin on 6 October 2020
Hi Norm, Lets see if we can track down those reeds for you! :) I have just created enquiry #445667 in our system for you so that our Customer Service legends can investigate and get back to you with a price and avaiability! Make sure to keep an eye on your emails and we will be in touch soon! Have a good one! Cheers, MXstore
MXstore Response

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