boyesen rad valve or Vforce3

Discussion for swapping a KDX motor in a MX frame...
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kx200
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boyesen rad valve or Vforce3

Post by kx200 »

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.
Last edited by kx200 on 08:44 am Apr 16 2015, edited 1 time in total.
Adamnb1
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boyesen rad valve or Vforce3

Post by Adamnb1 »

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.
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Re: boyesen rad valve or Vforce3

Post by Ed Up »

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.
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Tioli
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boyesen rad valve or Vforce3

Post by Tioli »

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
2001 KX125 with a 1997 KDX Tioli Hp motor

My KDX journey starts at the bottom of this page:
http://www.trials.com.au/forum/viewtopi ... &start=160

Trials.com.au / Forum / All about...me! / My long time friend the prancing horse / page 9
cornishwrecker220
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boyesen rad valve or Vforce3

Post by cornishwrecker220 »

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

Enough said ! :supz:
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Tioli
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boyesen rad valve or Vforce3

Post by Tioli »

Maybe you can try both and tell us
2001 KX125 with a 1997 KDX Tioli Hp motor

My KDX journey starts at the bottom of this page:
http://www.trials.com.au/forum/viewtopi ... &start=160

Trials.com.au / Forum / All about...me! / My long time friend the prancing horse / page 9
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Re: boyesen rad valve or Vforce3

Post by fuzzy »

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.
'91 KDX 200 Project $300 KDX
'95 KDX 200 Project $600 KDX
'94 WR 250 Always a project
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Re: boyesen rad valve or Vforce3

Post by KDXohio »

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!
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Re: boyesen rad valve or Vforce3

Post by Crankn »

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?
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Re: boyesen rad valve or Vforce3

Post by Tyl3r »

Did you ever end up experimenting and try both?

I was wondering which one I would want also.
04/05 KX220 Hybrid all decked out
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Re: boyesen rad valve or Vforce3

Post by 6 Riders »

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 :mrgreen: .
newbbewb wrote:^what he said.
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*side note...I'm drunk, so try to read what I'm trying to say, instead of what I actually type
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Re: boyesen rad valve or Vforce3

Post by Tyl3r »

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!
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24 KTM 300XC-W Cheater bike
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Re: boyesen rad valve or Vforce3

Post by 6 Riders »

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.
newbbewb wrote:^what he said.
masterblaster wrote:Man 6 riders you rock.
*side note...I'm drunk, so try to read what I'm trying to say, instead of what I actually type
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KDXohio
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Re: boyesen rad valve or Vforce3

Post by KDXohio »

I have the rad valve and love it!
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Tyl3r
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Re: boyesen rad valve or Vforce3

Post by Tyl3r »

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... :hmm:
04/05 KX220 Hybrid all decked out
18 KTM 500 EXC-F Dual Sport/Sumo toy
24 KTM 300XC-W Cheater bike
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