Challenging Conventional Wisdom about RAD Valve

Questions and Answers about the best carb and Head mods available for the KDX.
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doctord23
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Challenging Conventional Wisdom about RAD Valve

Post by doctord23 »

I have read several threads stating the Boyesen RAD valve was a waste of money. Now I'll give you that I bought mine used at a bargain price, but let me share my results.

Test subject: 2004 KDX 220; RB head and carb mods, FMF desert & silencer; fresh top end; properly jetted.
I have been running a Vforce3 reed cage. Bike Ran strong with good low end and strong top end. I have had this RAD valve laying around for awhile because it didn't come with the rubber boot. I was Looking to buy the boot so I could try it, but before I did, I made a boot out of an old radiator hose to try it.

Results: the bike just rips now with a definite increase in power throughout the rpm range. Riding up my uphill gravel driveway, the bike now wants to power wheelie when the power valve opens in third gear. It felt like I was on my KX500 (it has a RAD valve too). Your results may vary but I love it. Time to order tha correct boot.
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rbates9
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Post by rbates9 »

Are you looking to get rid of your Vforce 3?
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Indawoods
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Post by Indawoods »

I know the RAD functions... I just am not sure to what extent. I passed right over it from post after post on how ineffective they were... and they were not cheap!

KDXButtfly has one for sale!
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doctord23
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Post by doctord23 »

>|<>QBB<
rbates9 wrote:Are you looking to get rid of your Vforce 3?
Saving it for my future hybrid.
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Julien D
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Post by Julien D »

I've heard the same. The benefit from rad valve as opposed to 607 power reeds does not seem to justify the difference in price.

I've also heard many times that while the rad valve works better on some bikes than the VF2/VF3, I've heard this doesn't hold true for the KDX.

I don't know, don't guess I care either. The 607's seem to work VERY well for me. I will say this is the first time I have seen a post stating improvement going from VF3 to Rad Valve. I guess maybe it depends on your setup?
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scheckaet
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Post by scheckaet »

maybe the jetting was spot on FOR the rad and not so spot on for the vf3?
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kdxmaniac
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Post by kdxmaniac »

>|<>QBB<
Indawoods wrote:
KDXButtfly has one for sale!
rad valve for a 200?? how much??!! im interested.
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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kdxmaniac
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Post by kdxmaniac »

i run rad valves on both my ktms.........love them. i could DEF tell a diff. they pull better from bottom to top..........esp mid to top. i havent run the kdx on a rad valve.............YET! but in the verrrryyy near future.
my bikes
-------------
96 ktm 300
96 XR400R
07 hayabusa
77 kz 1000
85 goldwing 1200
02 BIG DOG PITBULL

gone but not forgotten
96 kdx 200
98 ktm 380 "because it dang near killed me!"
97 ktm 360
96 ktm 250
93 wr 250
94 dr 350s
93 kx 250
07 gsxr 1000
99 bandit 1200
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