Rad valve

davidg

Member
Apr 30, 2002
193
0
I've read that the rad valve is suppose to help throttle response, but also add a little on the top end. Does it, help with the top end? I have a 220 and just put on the woods pipe and have no regret about not getting the rev pipe ( really like the bottom end). But I would still like get a little more on the top end.
 

70 marlin

Mi. Trail Riders
LIFETIME SPONSOR
Aug 15, 2000
2,960
2
my rad valve is sitting on the shelf. bike runs better with out it.
 

jeffw

Member
Nov 27, 2001
172
0
Check out C-Dave's take on this at justkdx.dirtrider.net/hopup.html After reading this I took his advice and just put Boyesen Power Reeds, Part #607 reeds in the stock cage.

To be quite honest I can't tell the difference between these and the stock reeds, but that may be because I don't spend a huge amount of time tuning my jetting. BTW, my bike is a 200 not a 220.
 

fishhead

die you sycophant !
LIFETIME SPONSOR
May 22, 2000
966
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on my 220 I had a ported cylinder, rev pipe,bored and plated carb, squish band modified on the head, and the rad valve made a noticable improvment over the stock reeds, power reeds and pro reeds. Tried em all! It was on the order of magnitude of the rev pipe install. My take on the controversy is that riding style and rider preference determines the suitability of the rad valve. It may not be for everyone but it's not snake oil. Just for fun i installed one on my 01 250 ktm and it woke it up and smoothed out the power delivery.

The stock reed block on the kdx is not state of the art so some benifit can be had in that area. There is a loyal following of other brands as well.
 

dirt bike dave

Sponsoring Member
May 3, 2000
5,348
3
I had RAD valves on both my '90 200 and my '91 250. Both engines worked very well, but it's hard to say how much difference the valves made as I made other jetting changes at the time of installation.

IMO, things like proper jetting, a steering damper and good suspesnsion will help performance far more than a rad valve. But if you've done everything else first and still have some money, you might as well put a rad valve on.
 

canyncarvr

~SPONSOR~
Oct 14, 1999
4,005
0
The boyesen product is an improvment over OEM reed setups or power reeds on the OEM cage.

It holds not a candle to the MotoTassinari DeltaForceII.

There are a host of reasons why.

But, seeing as boyesen has recently HUGELY reduced the cost of their valve (cuz they KNOW their competition has 'em beat? ;) ), I imagine riders will continue to waste their money buying rad valves.

...imo :)
 

davidg

Member
Apr 30, 2002
193
0
Thanks for your input guys. Canyncarvr can you tell me what the Delta Force II did for your bike, better throttle response, more top end? Did it fit properly, without modifications? I was only looking at the rad valve because rocky mountain didn't have the delta force listed for 2002 production year. Just the 89-96 kdx200/220.
 

davidg

Member
Apr 30, 2002
193
0
Correction, the r/m has the delta force II listed on line for my bike. Just not in my catlog.
 

fishhead

die you sycophant !
LIFETIME SPONSOR
May 22, 2000
966
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Rumor has it the o3 ktm 250 sx will have a rad valve same as the 01 and the 125sx will have the moto tassinari. Wonder whats thats all about?
 

Razorback

Member
Jul 12, 2002
55
0
Recently insatalled a Rad valve on my 220.It does help top end some but I like the low and mid range throttle response.It gave the bike a little more torque while I didn't have to open the throttle as far or rev the engine as much.That makes riding in tight or loose conditions easier for me.I think it's worth the money.
 

CMcCarthy

~SPONSOR~
Apr 22, 2002
245
0
As I posted elsewhere, removing the RAD valve from my bike turned it into an axe wielding barbarian in the mid range. It is almost like the RAD was costing me power, not adding. I'm absolutely stumped.
 

Speedy

Member
Nov 12, 2001
247
0
Just my opinion but all of your bikes are not tuned the same. You all have made minor adjustments to the motor by messing with airbox,carb,porting and pipe etc. You know somethings are gonna work better then others depending on what youve done to your application. Do what you can do, if it works great, then fine!!!! If it doesnt then try something else. No 2 bikes are the same, or are they? The Rad valve came on my bike, and i bought new fiber reeds for it. It works Great!!! Yiiiii-Peeeeeee for me. lol But its just my 2 cents.
 

davidg

Member
Apr 30, 2002
193
0
Thanks for all of your input guys. I think I will wait for while before I change anything. I'm running my first H/S in two weeks and only have this weekend to make sure the bike's running right.
 
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