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Just wondering what everyone thoughts are on the best 220 carb replacement? According to these parameters:

No elevation change factor
Pro Circuit Platinum Pipe / silencer
Stock motor


I have an RB carb on my 200, and its great. As we know they are unavailable. Thx for the replies!!

I thought Ron Black was still selling new, modified carbs but would no longer modify an old carb. Of course I've been out of the loop on that for almost a year. If I couldn't get a new carb from Ron, I'd go with Lectron.

RB carb all the way, hands down! If he isn't doing new carbs still then the PWK 35 AS. I have a Lectron on another bike and I'm not sold on it. Maybe if you like a more mellow feeling bike, and no real tuning after you get it set up, then the Lectron might be for you. Just know they fit like crap on a KDX. Of course, I only change needle clip position on my RB carb from winter to summer and the main only if I ride above 5000" by one size. Super easy carb to tune IMO/IME.

Looks like RB will sell you a new modified OE or AS carb. I have his carb on my KDX and love it. I have always wanted to try a Lectron.

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

doakley wrote: 12:25 pm Nov 18 2021 I thought Ron Black was still selling new, modified carbs but would no longer modify an old carb. Of course I've been out of the loop on that for almost a year. If I couldn't get a new carb from Ron, I'd go with Lectron.

As of my last email from Ron in mid August, he didn't have any carbs and didn't know when he would have them, if at all.

SS109 wrote: 04:34 pm Nov 18 2021 RB carb all the way, hands down! If he isn't doing new carbs still then the PWK 35 AS. I have a Lectron on another bike and I'm not sold on it. Maybe if you like a more mellow feeling bike, and no real tuning after you get it set up, then the Lectron might be for you. Just know they fit like crap on a KDX. Of course, I only change needle clip position on my RB carb from winter to summer and the main only if I ride above 5000" by one size. Super easy carb to tune IMO/IME.

I am not crazy about the price of the Lectron and the issues with the install. Although I know many guys have made it fit, I want a bolt on carb with zero headaches esp after seeing the price!!!

I've ridden a 200 with a Lectron, stock motor except for an FMF Woods pipe. It is a sweet ride with a wide and predictable power delivery and revs out really high. My 220 has a new OEM RB modified carb. Engine has Boysen reeds, FMF Rev pipe and RB modified head. It is **** hot compared to the 200 in my opinion; feels more like a race bike than my buddy's 200. I think I rev out just as high as my buddy's 200 now but haven't done a side by side comparison since the RB mods. Not a fair comparison since there is more difference than just the carbs. Given my choice though, I'd take the RB first.

I was patient and was able to get a carb from Ron this past Spring, but I think he only gets in a batch once in a while.

I've really enjoyed the Lectron on my 200. The only pain was getting it fitted, otherwise I've leaned it out a quarter turn from stock and it runs crisp. I am about to purchase it again for my 220, so at some point I'll post feedback. The price is high for sure, but I'll keep these bikes forever, so if you break it down it really is just a cry once type of purchase. Good luck!

I upgraded to a 35mm carb from stock 33. Bought on ebay. No need to mess with jets, runs just fine as is.

@greenblood67 wrote: 06:07 am Apr 07 2026 I upgraded to a 35mm carb from stock 33. Bought on ebay. No need to mess with jets, runs just fine as is.

Greenblood, what performance differences with the slightly larger carb are you experiencing?

Definitely the newest version Lectron Billetron Pro Series or SmartCarb SC3 34mm, but not any of the previous Lectron versions unless you got a good deal used on them and were able to get the correct metering rod and settings. The poll only has a name brand, not carburetor model despite there being five different models that are pertinent for our bikes made by the same manufacturer (Lectron).

I will soon have a SmartCarb SC3 34mm in my hands in addition to owning two different Lectron carburetors including the second most recent generation of the Billetron Pro Series, but with the newest Xcelerator metering rod added to it.

Those two carburetors are undeniably the best for those who understand them and give them a chance, as opposed to old timers who swear them off without actually knowing how they work or even giving them a chance.

My #3 would be my Ron Black modified 36mm bored divider plate installed Quad Vent PWK35 Air Striker carb.

All three are absolutely excellent carbs. They all beat out the stock carbs and the new genuine $425 Keihin PWK 35 Air Striker versions.


There are so many fake forgeries of the PWK 35 Air Striker on eBay, Amazon, and elsewhere nowadays, but if you use genuine Keihin parts and verify the needle jet orifice size is correct, and properly tune them, including using a genuine Keihin slide needle and tossing all the metering parts that came stock with them, you can get those to run good, better than an original worn out genuine Keihin carburetor.
You'll have less than $200 into them if you buy the $65 version and not the identical $180 fake cloned version if you go with the cheap ones, but I still don't recommend it whatsoever due to long-term durability concerns.

Ahhh.... I now see that this is a 4.5+ year old thread/poll which was recently dredged up!
The poll options predate the 3 newest Lectron versions as well as the SmartCarb SC3 34mm KDX fitment, which is brand new as of April 2026, not yet shipping out even, but very soon...

Internet forums are like milk. Check the date! :-)

I installeda Keihin35mm, I don'tknow the exact difference, but I can tell you that it's more responsive throttleand a littlefaster overall

billie_morini wrote: 11:30 am Apr 07 2026

@greenblood67 wrote: 06:07 am Apr 07 2026 I upgraded to a 35mm carb from stock 33. Bought on ebay. No need to mess with jets, runs just fine as is.

Greenblood, what performance differences with the slightly larger carb are you experiencing?

Chuck78 wrote: 11:53 am Apr 07 2026 Those two carburetors are undeniably the best for those who understand them and give them a chance, as opposed to old timers who swear them off without actually knowing how they work or even giving them a chance.

I assume this was directed at me, ref: our conversation in the Smart Carb thread.

I don't like meter rod style carbs.

They are not as crisp as a properly jetted "traditional style" carb. They can't be by their very design. The metering rod smooths out power delivery. I do not like that. It makes the bike feel lazy and mushy. I like sharp, quick response for the riding that I do. If you like the softer power delivery for the riding that you do, it might be a better choice, but don't try to make the Smart Carb out to be something that it isn't. Some riders liked the mushy feeling of the old CV style carbs too, and that's fine if that's what suits the riding that you do.

I understand the Smart Carb, how it works, how to tune them, and I am very familiar with the Keihin PWK family, having tuned it extensively over the years. The PWK has always given me the best results throughout the elevation range that I ride (4000'-9000') The issue I've seen is that people go from a tired, old, improperly jetted PWK to a smart carb, and notice the improvement it gave, so they stop there. Me, I like to squeeze every ounce of performance AND rideability out of my machines, fine tuning is in my blood. I've never been able to do that with the meter rod carbs vs the "traditional style." There just isn't as much adjustability there.

Slick_Nick wrote: 09:37 am Apr 09 2026

Chuck78 wrote: 11:53 am Apr 07 2026 Those two carburetors are undeniably the best for those who understand them and give them a chance, as opposed to old timers who swear them off without actually knowing how they work or even giving them a chance.

I assume this was directed at me, ref: our conversation in the Smart Carb thread.

I don't like meter rod style carbs.

They are not as crisp as a properly jetted "traditional style" carb. They can't be by their very design. The metering rod smooths out power delivery. I do not like that. It makes the bike feel lazy and mushy. I like sharp, quick response for the riding that I do. If you like the softer power delivery for the riding that you do, it might be a better choice, but don't try to make the Smart Carb out to be something that it isn't. Some riders liked the mushy feeling of the old CV style carbs too, and that's fine if that's what suits the riding that you do.

I understand the Smart Carb, how it works, how to tune them, and I am very familiar with the Keihin PWK family, having tuned it extensively over the years. The PWK has always given me the best results throughout the elevation range that I ride (4000'-9000') The issue I've seen is that people go from a tired, old, improperly jetted PWK to a smart carb, and notice the improvement it gave, so they stop there. Me, I like to squeeze every ounce of performance AND rideability out of my machines, fine tuning is in my blood. I've never been able to do that with the meter rod carbs vs the "traditional style." There just isn't as much adjustability there.

Nick, I actually was not in any way directing my comments which you'd quoted at you whatsoever, but I did have another KDX owner in mind who fits the description far more appropriately than you do... he's not a member here. As well as a lot of cranky old 60+ year old guys who still think that Nikasil plating is a scam, and that all cylinders should be sleeved... A lot of people, particularly people in that age range and up, base their opinions on Lectron technology from the 1980's & 1990's. Things have changed significantly in the past several years with metering rod carb technology.

The newest generation of Billetron Pro Series is an incredible carburetor, and the Smart Carb SC3 34mm looks incredibly promising as well.

But to you, I will say, you must never have ridden a well tuned Lectron Billetron Pro Series with the new X-rod or Xcelerator metering rod. They are amazing.

I'll be getting a Smart Carb SC3 34mm here in the near future as well to compare. Although the Smart Carb might fit your description a little bit better for those who just are content with the metering rod they have and don't experiment with tuning it better for different throttle ranges, nor consulting Smart Carb tech support if they find that different portions of the throttle range needed leaned out or enrichened slightly....

It's often theorized, when comparing metering rod carbs, that a Keihin/Mikuni jetted carburetor really potentially has such a strong hit because it starts dropping off in adequate fuel metering delivery just before the hit, due to the lack of fine-tuning ability that the jet needle clip positions have, and then when it reaches the RPM / throttle position that it's more ideally tuned for, that's where a good part of the hit comes in (as well as the power valve opening fully of course).
My old style Lectron on my RB headed Pro Circuit piped 220 actually had a significant hit until I tuned in a little bit better, which helped smooth out the hit as best as possible, which is why I support the above theory regarding Keihin carbs having a greater hit. It's not so much that they have a strong power surge, it's theorized that they have a strong power surge because they are lacking in power directly below that.... Which is perceived as making more power because it comes on so explosively after it's performance was less than explosive.
The metering rod carbs have so much more fine-tuning ability, as opposed to 1mm clip position increments to raise or lower the jet needle. That's definitely something to consider that is a very valid supporting bit of evidence. One clip position is a MASSIVE fueling difference in the mid-range throttle positions.

With my old style Lectron though, it was always a bit rich down low although it delivered incredible fuel efficiency still, I couldn't get the mid-range exactly where I wanted it without having a rich bottom end and more pipe bang on low throttle or closed throttle deceleration (@ higher RPM) than what I cared for. That probably constituted the need for a different metering rod tbh, but I never bothered with that as I'd jumped on the Billetron train when that came out.

I would love to see some really in-depth dyno tuning runs of both to be quite honest, Keihin vs Billetron Pro vs SmartCarb SC3, but what I do know is, the metering rod carbs deliver significantly better fuel range and fuel mileage, as well as better throttle response, while delivering pretty impressive power.


I really truly feel that peak power is going to be the same with either type of carburetor, but throttle response, smoothness, low end power, and of course fuel efficiency and fuel tank range are the big benefits on top of being a brand new carburetor most of the time versus I worn out original or risking buying a fake Chinese counterfeit Keihin....

The cost is high, however, but a genuine Keihin now costs $430 or $450.... $599 gets you a SmartCarb SC3 34mm. The Billetron Pro is in the stratosphere, however.... $799, & I have never noticed them to ever go on sale, not even Black Friday type deals.

I've used both, PWK and Lectron.

I love my RB modded PWK on my KDX plus it fits perfectly. I love the super snappy response I get from it and it has been stone cold reliable. On my '11 GG EC250R I have an old school Lectron. It's not as snappy but it really doesn't matter on that bike because it also has a auto-clutch so they work well together. Yes, I know how to tune metering rob carbs. Took me quite a while to really dial in the one on my GG to where I was ok with it. If that bike didn't have the auto-clutch I would put a PWK back on it in a heartbeat over the old school Lectron.

I've heard good things about the newer Lectrons and SMartcarbs but I've also heard of some never being able to get them dialed in right. With that kind of info out there, especially those with metering rod carb tuning experience, it makes it where someone like me isn't will to fork out such a huge sum of cash on something that might, or might now, work.

SS109 wrote: 08:23 pm Apr 09 2026 I've used both, PWK and Lectron.

I love my RB modded PWK on my KDX plus it fits perfectly.

I've heard good things about the newer Lectrons and SMartcarbs but I've also heard of some never being able to get them dialed in right.

Keep in mind with some users never being able to get the metering rod carbs dialed in right, there are also a countless amount of people who are never able to get jetted Keihin and Mikuni carbs dialed in right.... And also an equal number of people who think they have their carbs dialed in perfectly, yet on many others standards, they are far from perfect, but ignorance is bliss in those cases... until they experience otherwise! I have blown a few minds by swapping needles and jets and even just dialing the air screw in as to how much more performance was left on the table prior.

I have an RB 36mm bored PWK35 Air Striker Quad Vent with divider plate etc. it's an excellent carburetor, one of the best. But with the fuel efficiency of these latest generations of metering rod carbs, and the incredible throttle response, I very much appreciate their technological advances and performance.

Chuck78 wrote: 10:06 pm Apr 09 2026Keep in mind with some users never being able to get the metering rod carbs dialed in right, there are also a countless amount of people who are never able to get jetted Keihin and Mikuni carbs dialed in right.... And also an equal number of people who think they have their carbs dialed in perfectly, yet on many others standards, they are far from perfect, but ignorance is bliss in those cases... until they experience otherwise! I have blown a few minds by swapping needles and jets and even just dialing the air screw in as to how much more performance was left on the table prior.

Yes, I know. Like I mentioned above, I know how to tune regular carbs and metering rod type carbs but that's just speaking for myself. Thing is that not everyone can really tune a carb and it might as well be voodoo to them. A metering rod carb won't solve that problem so there's really nothing we can do except tune it for them, tell them to take it to a shop which who knows how good that would actually be, or recommend they get an EFI bike.

Chuck78 wrote: 10:06 pm Apr 09 2026I have an RB 36mm bored PWK35 Air Striker Quad Vent with divider plate etc. it's an excellent carburetor, one of the best. But with the fuel efficiency of these latest generations of metering rod carbs, and the incredible throttle response, I very much appreciate their technological advances and performance.

I would be willing to try one but not on my dime. I have my RB 36mm bored PWK35 original type carb dialed in darn near perfect so it wouldn't be worth spending the money on one for me. I can't see it giving me enough performance improvement to justify the cost. Maybe if my bike had a worn out carb I would seriously consider one.