KDXRIDER.NET

I recently picked up a KDX220 and honestly part of the reason I even considered a 220 was when I started my search last year I read all the reports about the RB head mod and RB carb mods and what a difference it makes to the 220.

As my luck would have it, it now appears there is no more RB designs. I haven't gotten a reply to my emails requesting a carb or head mod and it's been a while.

Everyone raves about Ron's great customer service, and while I don't doubt that, it sure would be nice if he would update his website or close it or something so people like myself aren't left wondering what is going on. It was only by searching here I discovered he apparently has retired.

Anyway perhaps he will eventually reply to my email and I can get one of his carbs and heads, but assuming he doesn't, are there any other reasonable alternatives to his 220 head mods and modified carb?

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After trying to find an alternative, I have I come up with 2 alternatives:

Ken O'Connor Racing kenoconnor07@aol.com $80 shipped

Arnie Cooper. arniecoo@q.com $150 shipped

Both of them want to know the current squish measurement.

There really isn't any magic to the head mod. The idea is to reduce the dimension of the squish band to .050" to improve combustion.

FYI: Ron is taking work and I have had a few email conversations with him regarding his carbs. Like he states, if he cant do it at his own pace, (semi-retired) he's not interested in the work. As stated previously he does not mod carbs, but sells new oem/modded PWK carbs.

Don't have much to add to that except I recently purchased a new OEM/modded PWK carb from Ron and had the head work done as well. (Note, you do NOT have to do the measurements with solder on the 220). That with an FMF desert pipe and Boysen reeds have really fired up my 220!
I understand you can get similar with Jeff Fredette as well.

Ron is semi-retired but is still working last I heard. Contact him about buying a new carb. I guarantee you won't be disappointed with it.

It's been over a week since I emailed Ron and have not heard back yet.

I told him in my email I'm not in a hurry and want to buy a new carb (understand he is no longer modifying used carbs)

From what I gather the head mods he does are good, but not so different than what others can do, it's more the carb mods that are "special"

If any of you have an inside inline with Ron and can get a carb and want to resell to me at a little profit, let me know.

Just an update. I did eventually hear from Ron and I just got my new carb and modified head back (which he did quickly). I need to dial in the jetting but overall first impressions from the first ride is these mods do certainly make a very noticeable difference. Outside of the RB mods the only non-stock thing on my bike are the 607 reeds. I probably need to pull the lid off my airbox and get a pipe to get the full effect, but so far so good.

Thanks for the ride report. Enjoy!

If I recall correctly, Ron's mods pretty much are designed for removal of the airbox lid and a different pipe. Of the 220 that would be the FMF rev or desert pipe. Think of Ron's mods as getting more mixture into your bike . Now to truly realize the full benefit you need to let all those extra combustion gasses out better.

Just an update. I played around a bit with jetting (I'm at elevation) and am now very happy with the RB head and Carb, basically I'm confirming all the glowing reports I had read and am glad that Ron was able to do this for me in his semi-retirement.

I still have the stock pipe and while I don't doubt an FMF could probably get me even more, I like the relatively quiet stock pipe (although it is heavy) and the stock silencer that doesn't have to be repacked. Eventually I will probably dent the stock pipe and upgrade to an FMF pipe, but I find the engine performance to be quite satisfactory now, which of course was not the case when everything was completely stock. I recently sold my older Yamaha WR250 (2 stroke) and while the RB modded KDX220 still doesn't have quite the total power that did, the difference is really not that great, especially in the power delivery in the mid range and lower which is where I spend most of my time riding anyway.

Get the FMF desert/rev pipe and keep the stock silencer. I also recommend a pipe guard like Flatland racing. The pipe makes a HUGE power increase.

As far as an alternative...I picked up a 220 with a plug and play Air Striker from JD Jetting. It runs just as well as the RB carbed 220, I also have. Both have the RB head mod, both have a full FMF exhaust (desert pipe and Turbine Core). If the RB carb is not an option, I would but the JD Air Striker in a second.

Juanito wrote: ↑01:12 am Apr 16 2021 As far as an alternative...I picked up a 220 with a plug and play Air Striker from JD Jetting. It runs just as well as the RB carbed 220, I also have. Both have the RB head mod, both have a full FMF exhaust (desert pipe and Turbine Core). If the RB carb is not an option, I would but the JD Air Striker in a second.

Could you please provide a link? Curious as all the plug and plays I found on JD were too big.

Sorry, I do not have a link since I did not do the swap. What I can tell you is that the shop that did the swap just called up JD, told them what they wanted, it arrived, and it ran perfectly with no adjustments to jetting other than air screw and idle.