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I emailed Ron about a new carb yesterday, got an email in my spam filter that said the email address I linked from the RB-Designs website was incorrect, so I emailed him again and just got a reply that he " has retired and no longer doing the carb work"...
I am beyond bummed....
Does anyone know if Fredette does the same kind of thing?

Wow, that's a real bummer he isn't doing them anymore.

The only place I see doing the divider, slide, and boring type mods is https://richstayloredporting.com/vintage_Venturi.html who does have a good reputation in the vintage Hodaka circles. That would probably get you 90% of the way of an actual RB carb.

SS109 wrote: ↑02:04 pm Mar 24 2023 Wow, that's a real bummer he isn't doing them anymore.

The only place I see doing the divider, slide, and boring type mods is https://richstayloredporting.com/vintage_Venturi.html who does have a good reputation in the vintage Hodaka circles. That would probably get you 90% of the way of an actual RB carb.

Thanks for the link - I'll have to check them out...
I wish Ron would take the website down - or remove the KDX carb info - it's frustrating to see it on the website and know that I can't get it any longer!

I did contact Jeff Fredette about carb work, apparently he does some mods such as boring, but I'm not sure how much he goes into them beyond that. He doesn't seem to like the plate mod based on his reply to my email... Quoted a price of $93.00

Looks like Ron still sells a brand new replacement carb for the KDX. 6 months ago I had him do a head mod as a spare I purchased off eBay.

https://www.rb-designs.com/rb_designs_llc_009.htm

K50X200 wrote: ↑03:29 pm Mar 24 2023

SS109 wrote: ↑02:04 pm Mar 24 2023 Wow, that's a real bummer he isn't doing them anymore.

The only place I see doing the divider, slide, and boring type mods is https://richstayloredporting.com/vintage_Venturi.html who does have a good reputation in the vintage Hodaka circles. That would probably get you 90% of the way of an actual RB carb.

Thanks for the link - I'll have to check them out...
I wish Ron would take the website down - or remove the KDX carb info - it's frustrating to see it on the website and know that I can't get it any longer!

I did contact Jeff Fredette about carb work, apparently he does some mods such as boring, but I'm not sure how much he goes into them beyond that. He doesn't seem to like the plate mod based on his reply to my email... Quoted a price of $93.00

If you contact him you should let him know the KDX community would be interested if he started offering a carb like Ron's. Maybe he could take over that biz. Maybe the head mods as well!

Yeah, I'm more interested in the black magic behind it. Once you give him your squish, what exact profile does he machine in the head? As well as the exact ID profile of the carb and wing dimensions......... as a dirtbike guy and mechanical engineer employed at a large machine shop, I got access to all sorts of goodies for design and manufacturing. It's what I do, But Ron Black & Eric Gorr & Kevin Cameron & Graham Bell & Gordon Jennings I am not!!! I'm just a schmuck who rides and fixes

Side note though, I did reach out to the smart carb guys a few months ago to see if they'd give me detailed OD dimensions of their carb - I was going to 3D print a mock up so I could figure out some sort of way to fit it in the KDX, be that airbox mod, intake mod, fame mod or all of it......... but there's really nothing in it for them so they don't seem interested.....

Molly's 70 wrote: ↑04:01 pm Mar 24 2023 Looks like Ron still sells a brand new replacement carb for the KDX. 6 months ago I had him do a head mod as a spare I purchased off eBay.

https://www.rb-designs.com/rb_designs_llc_009.htm

The modded new carb is what I inquired about when he replied with the retirement notice...
If he's really getting out of the game he should pull those items off the website - or shut it down completely.
I guess it's possible that as our bikes get older, he gets so few inquiries that he just doesn't bother removing them from the site.

Kawibunga wrote: ↑05:05 pm Mar 24 2023 Yeah, I'm more interested in the black magic behind it. Once you give him your squish, what exact profile does he machine in the head? As well as the exact ID profile of the carb and wing dimensions......... as a dirtbike guy and mechanical engineer employed at a large machine shop, I got access to all sorts of goodies for design and manufacturing. It's what I do, But Ron Black & Eric Gorr & Kevin Cameron & Graham Bell & Gordon Jennings I am not!!! I'm just a schmuck who rides and fixes

Side note though, I did reach out to the smart carb guys a few months ago to see if they'd give me detailed OD dimensions of their carb - I was going to 3D print a mock up so I could figure out some sort of way to fit it in the KDX, be that airbox mod, intake mod, fame mod or all of it......... but there's really nothing in it for them so they don't seem interested.....

Ron's done so many KDX200 heads he doesn't even need your squish - you just sent in the head - which I never did, even though I bought an additonal head from eBay to have him work his magic on...

If you contact him you should let him know the KDX community would be interested if he started offering a carb like Ron's. Maybe he could take over that biz. Maybe the head mods as well!

So, I just got off the phone with Rich from https://richstayloredporting.com/. He does a more extensive version of Ron's venturi plates (which he seemed very unimpressed with! ) - 3 on each side of the slide - 6 total... Also a little more expensive, $225 - I believe. He's a pretty fast talker, so there was a lot of info being layed out in a short phone call
He also recommends an Intelajet install with the venturi dividers - which is close to another $200 (purchase and install), so with a new carb and all that work I'd be in Lectron cost territory!
I really didn't get into the head mods, So if you want to get in touch with him for that, it may make him start to wonder about how much KDX work is out there!

Hmm, that sucks. I'm a little disappointed that he didn't like Ron's work since we all know his work was excellent. That makes me wonder about him.

I recently had an in-depth discussion about some of these mods with Jeff. He actually knows quite a bit about them. His counterpoint on the wing /divider plate was that where it improves throttle response in one area, it robs it in another. He found there’s more ways to skin that cat with better rideability. I’ve also seen tech data somewhere that supported this.

He’s pretty close to retiring too, would be nice if someone bought him out and kept the business chugging along.

As an amateur machinist, I've studied my RB carb thoroughly, and the modifications aren't too difficult to complete, just time consuming.

Ron is still doing 220 head mods, FYI. He's just not doing carb mods, or at least he's retired to the point where he will not do used carb mods, which is what he told me back in 2020 or early 2021.

Yesterday I inquired about 220 head mods, and Ron said he's still doing this service.
"Yes, I’m still doing the head mods for the KDX 220. Let me know if you are interested." -Ron Black

He said back in 2020 that he will probably do new carb mods again, but just not in 2020 or 2021 due to the high cost of materials and parts involved.
He told me then that he no longer will do any used carb mods, especially considering how most 15-25+ year old carbs are worn out by now.

I'll be sending out 2 or maybe 3 220 heads to Ron Monday or Tuesday now
One he may not want to do as it'd perhaps require a bit more research. I bought a 223cc 70mm bored + replated + ported 220 cylinder, & the previous owner parted out the bike with low hours on the 223cc ported cylinder. The head wasn't matched to the +1.0mm overbore, and I hope to get Ron to cut the head 0.5mm more diameter on the combustion chamber area. Bigger piston also increases the compression ratio, so Ron may deem it necessary to take a little more out of the combustion chamber dome to accommodate, but maybe that's more research and math than a guy who retired from this work will want to do.

Looks like I waited to long to get my 220 head done, his website still offers the service, but when I emailed him a couple days ago to get instructions on sending it in, he replied that he doesn't do it anymore. Maybe Fredette? His site offers it, wonder if anyone has had him do it.

Darnit... I spoke to him March 26th and he said yes he's still doing 220 heads, but I had a 3rd head to send him that was questionable on minor combustion chamber damage, and he said to send pictures of the third head and he'd advise.

Well, my Mom's battle with terminal cancer worsened and I wasn't able to tear down that bike to photograph the head and send it in yet. Mom just passed away after a long battle, and I was hoping to go home 1 day this weekend and tear down the flogged '99 220 engine to remove the head...


Now I'm wondering myself if Fredette or Eric Gorr's head work is comparable to Ron's?!

Sorry for your loss.

Thank you

I'm thinking Eric Gorr 's head work is #2 next to RB, so I may send 1 head out to Gorr with my ported 223cc cylinder, as I've read on this forum that the head requirements really change with a ported overbored cylinder vs a stock bore stock porting cylinder...
And this porting is unknown to me, previous owner had it ported and bored/replated to 223cc at a shop in Canada called CV Tech.
The porting job looks REALLY NICE, but I don't have the best grasp on porting fundamentals to know much about what to expect out of it. I've been meaning to photograph it and a stock cylinder in identical shots of the various ports to do a side by side comparison on here, ThumperTalk, Dirt Rider, etc forums.

Does everyone else agree that the head reshaping needs to be tailored to each configuration, where a stock 216cc stock porting 220 cylinder is best with the standard offering RB 220 head work, but a ported 223cc cylinder would have different head shaping requirements?

Arne Cooper and Ken O'Connor Racing are 2 other viable options for head work. O'Connor is a little cheaper. Arne did a head for me and I believe he really know how to adjust chamber volume and squish band.

Arne can be found on ThumperTalk...somewhere.