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I have both and would like some feed back on what to use.
This will be for a H series 200. I will be running it with a 36mm Lectron Carb.
Also have FMF rev and torque pipes to try.
I had the Boyesen on my E series and the reeds last for ever!
The motor I bought had the vforce and have not got it installed in the frame yet.

don't have experience with the rad valve, but a few articles I read in the past indicated that the vforce3 is generally considered the better performer, which is why I bought one.

I've never experienced the boyesen but do have the vforce on my 200. Did the jetting, fatty pipe, and reeds at the same time. WOW, completely different bike, really fast and pulls good through full rpm range.

I can't coment on the rad valve but I completly understand the v force. What I like about them is:

1) The splitter plate for the top and bottom has a nice nose on it. If you can imagine air traveling into the reed block the area of the initial inlet tube is x. This is then devided into two. To keep the same area you will have to transition it quickly and a nose like a whale or jumbo will do the job. The reason why you need to maintain the same area as you travel down the intake is if you increase size speed slows and can cause turbelance which is even worse. If you shrink it to much you can loose volume but gain speed. There is a balance.

2)the reeds are on a much flatter angle this flatter angle means the reeds will open easier and not as much. This will give you earlier opening and longer duration.

3) the reed material is thin and easy to bend (see 2)

4) this set up is superior to any two stage reed pettle as the top one is thin (see 2) and the base one is thick to support the thin one so you don't get bounce or wobble at high speed. Thick is opposite to 2&3

My 2c so I got the VFORCE

Both Eric Gorr & Jeff Fredette recommend the boyesen rad valve .....that's why I have one fitted to my 220...

Enough said !

Maybe you can try both and tell us

The RAD Valve seems to wake up top end, but the V3 definitely adds off-idle power/response which is what most KDXers want. The RAD valve on most 250s seems better designed.

They both work great and since you have both the only way to tell which works better for you would be to install each and ride!

KDXohio wrote:They both work great and since you have both the only way to tell which works better for you would be to install each and ride!

Yeah that makes sense. Fit them both and you tell us what you think of them.
Am interested to hear about the Lectron carb you are using?

Did you ever end up experimenting and try both?

I was wondering which one I would want also.

Tyl3r wrote:Did you ever end up experimenting and try both?

I was wondering which one I would want also.

I made my decision when I found this; http://www.boyesen.com/overstock.php?ma ... =Rad_Valve Call them to order one. I bought the rad valve an extra boot (for my other KDX that already has a rad valve and needs a boot). With shipping it was $117 or there about. Rad valve looks brand new and came with carbon fiber reeds .

O wow, that's awesome! Enough to convince me which way to go! Wish I knew for sure what motor I was using so I could snag one up right now!

Thanks for sharing!

The rad valve fits all 89 and up KDXs...so, unless you are going with an air cooled motor, you should be good to go.

I have the rad valve and love it!

O shoot, the 200 and 220 use the same part number, did not see that at first!

I dunno, looking on ebay I saw 2 different places selling the VForce 3's for 125 bones. I am a nerd and really like the tech behind the VForce and how it has more reeds... I may lean that way when it comes time to get one.

I was hoping that someone may have tried both and can describe the differences they noticed in performance between the two...