The Best Carb Money Can Buy? | SmartCarb SC2 

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In the pre-FI era, it was common to use a Gunson Colortune see-thru sparkplug to visualize the colour of the fuel burning. You then tweak the carb mixture screw and or needle to get a nice blue hue for near ideal mixture. Too yellow means too rich, too white means too lean.

Those big claims about fuel economy and power need to be tested, i'm extremely skeptic

the catch? the price, obv. as for planet killing - enthusiast bikers, classic car drivers etc. are not the problem. we're a quite sustainable drop in the ocean compared to the real problems.

Smart carb has the best customer service hands down. I reached out after buying one second hand. They helped me thru multiple detailed emails, to get it setup, knowing full on I bought the smartcarb used. Cleaned up the mid range huge on my YZ285 big bore.

Good video. I've been running the SC2 on my Sherco for close to a year now. I ride big elevation changes, one ride may be at 2000' and the next at 9000' so not having to make any adjustments and the increased fuel economy is huge for me. It's all the advantages of FI without the added complexity and still retains the performance and feel of a carb.

Have the SC2 on my 250 SX, thing was different right off the bat. Instead of being an uncontrolled powerhouse, my bike became gentle and easier to ride thus helping my lap times without losing any noticable power. Gas lasts me 1 week instead of 3 days. Def worth

Regarding those stripped screws on the Keihin, have you tried using a JIS screwdriver? Using a normal Phillips on JIS screws (like Japanese carbs) is a recipe for stripped screw-heads. They *look* the same but they aren't.

I have one on my KX500 and it was the best decision ever. Runs strong regardless of temp or altitude like they claim, starts easy, and always idles smooth and steady. Just up to you if you want to drop the $800. I'm glad I did.

The reason for this carb being "self adjusting" is the same thing that happens on a normal carb; the thinner air decreases the vacuum signal, less fuel comes from the float bowl, and the bike runs essentially normal. Often times, when you go UP in elevation, the only thing you need to do is increase idle speed a bit. I've gone from 1,800 feet to 8,000 feet on many different 2 strokes (with quad vent keihins and TPS's, I might add) and many different four strokes (CV style carbs found on LTZs, Predator 500's, FCR Carbs on 250/450f's, Mikuni VM's and TM's on my old school vintage bikes) and the only thing I've ever needed to adjust on the four strokes is the idle screw. The only carb's I've ever needed to change jets with to not foul plugs were 2-strokes with the Mikuni TMX 36's and 38's, which are notorious for being very finicky. Maybe it's just me, but I don't understand how having only 1 main form of adjustment from idle to over-rev is an advantage. If you want the ease of adjustment, use a Dial-a-Jet on a normal carb, and save yourself enough money to do the next 3 or four top end jobs, lol.

Installed my SmartCarb on my 2017 YZ250X a few weeks ago and it's a night & day difference from the stock carb. Incredible performance!

Just saw a video by fortnine explaining whether a carb is better or fuel injection. Would recommend.

The PWK is a great carb, I have a worked KTM 380, I had to bore the carb out to 39.5mm from the stock 38mm so I could jet it. I like having 6 adjustment points with the PWK, it took some messing about, a number of different needle tapers etc but the bike is now crisp everywhere over the throttle range.

The British SU carburettor uses a metering needle that can be tuned by choosing a different taper or filing a flat on part of the needle. SU has a butterfly valve and constant velocity slide. David Vizard gas flowed the 1.25” to flow the same as 1.5”. There are some tips but it worked very well indeed. Biggest issue for altitude is the relatively narrow range of mixture adjustment for any particular needle. Saying that you can use an old style choke control to raise and lower the main jet. Set it half way for low altitude, full high for high altitude or full low for cold start.

About 10 yeats ago, I bought a 2002 KTM 520 exc, from the original owner. He was/is definately a tinkerer. He was a Canadian guy, who had relocated to SoCal. He was also, big into snowmobiles. The 520 was pristine! He had added a device, known as a dial-a-jet to it. Apparently this is a common mod to snowmobiles.???? I had no prior knowledge of it. He had it all set up, and gave me the manual for the dial-a-jet. After reading, and understanding the unit, I just rode the bike and still do...a lot. Even in very low temperatures, I never have to use the choke! Even first thing in the morning! I have ridden the bike at aea level, or below, and at 9000' elevation. 1 or 2 "clicks" on the dial-a-jet adjuster is all it takes. Incredible! Has anyone else had experience with these?

Great carbs, I imported one in 2014 & fitted it on my KX500, Corey from APT assisted me with the setup and it was quite straight forward. I did the quads4quads run from Carnival City down to Ballito without any issues related to the altitude changes. It’s worth the money. Great episode man, I recognized Rhino Park straight away.🤣

one of the great tuners descibed carburation as a controlled fuel leak i have a delloto 40mm pumper on my racing norton with an adjustable main jet a needle moving in and out of an oversized main jet via a threaded drain nut with a gland rotated by an old rev counter cable alongside the tank a long hill is needed turn the knob with wot till the motor comes on song then close the throttle a wee bit if the motor momertarily speeds up its weak so another half turn or so and its bang on then its needle /slde/pilot / cut away for the rest of the range binks made some fantastic carbs in the 20s notable the Rat trap with d shaped port and long reed type throttle plate full bore or nothing

Appears to be a good solution for many who aren't into cleaning or tuning the average carb for their motorcycle. Thanks.

Just discovered this channel sitting in PTA...great channel and great carb...love that someone is improving the high maintenance design.

Thanks for sharing (Also, there is a difference between Phillips and JIS screws. dot on the head means Japanese Industry Standard or something like it. Its a good upgrade to the workshop to get a set of JIS screwdrivers))

Holley came out with a carb for Harleys using this exact concept, flat sided needle and all. They called it QuikSilver. I have one on my shelf of shame along with a bunch of other carbs. In the beginning, after getting it tuned in, it seemed to be a very good carb. The main problem was that after a year or so of running it became almost impossible to keep running right due to internal wear in the carb body and slide, and in the needle bore. Replaced it with an S&S Super E and the bike has been running perfectly for over a decade. I don't think they lasted long on the market. Of course, this is a new manufacturer, and maybe they've overcome the wear issues.

That was a very well mdare video, mate! I'm running the SC2 on my KTM 300 EXC 2017 for the last 2.5 years and that's the best thing I did for my bike (along with the suspension).

I'm so glad my 150 came with this carb. It's so simple and the bike runs so clean.

Brilliant! An innovation as simple as the carburetor itself! The moment I saw it I under stood it, the complexity lies in the profile of the metering rod, which disappears as well once the maths are worked out.

Thank you for your video, I had never heard of this device before and found it very interesting (as a former motorcycle mechanic). It's good to see that companies are investing in developments that benefit the rider, their motorcycle and are less polluting whilst giving greater fuel range and power.

Having worked with carburetors for 40+ years, I found the SC2 concept to be very interesting. However the only feature that would be beneficial to myself would be the ability to easily adjust for altitude. On a single cylinder, single carb engine, the rest of the tuning is so easily done that it wouldn't be of any real benefit, regarding getting a base setting. When I'm working on a bank of 4 carburetors, then I'm always wondering why there isn't a simpler way as the carburetors have to be removed and replaced several times over as the various circuits are tuned, although that's only really a chore when you have a none standard set up in terms of the engine modifications and different carburetors, so you do not have a stock factory setting to work from. If you are racing then I guess the real crunch is whether the design really gives you all that extra power over a properly tuned stock carburetor, many 2 stokes are setup from the factory to run somewhat rich for engine longevity, rather than all out power and fuel efficiency.

I think you missed the biggest problem, they are expensive, would love to try one out since I ride summer as winter up in sweden and need to rejet my carb 2 times a year, but for me the sc2 cost twice the price of my bike ;)

I have same carb on my bike ride one time has lots more power then my mukuni had. Runs great at 3 to 5 clicks leaner. Still trying to get mine to idle as well. Revs great sounds great so smooth very good improvements over stock carbs 👍

Nice! It's about time they've taken a step in a different direction besides the plain Jane same old carburetor and changed the internals more than just the shape of the damn slides! It's about time and long overdue especially for the same fact you bring in up in the video, "the whole ripping a carb apart to tune it" part! Nothing's more frustrating than losing your E clip for the needle in dirt or grass! Can't say how many times it's happened before, but more than I'd like to think about! That's absolutely awesome stuff! Dial tuning just like an adjustable jet use to be. I have a personal problem with fixed jet sizes and have always wondered why? Outside it makes them tamper proof I guess and once it's set up with the right size it's good. VERY very annoying Stuff when you made engine or altitude changes and need more or less fuel! Wow really outside of fuel injection BS, which is OK, you just do not make the same power nor have the same throttle response with FI as opposed to a carb, sorry I've had plenty of experience with both and hands down a carb on the same exact engine will produce a few more HP and the throttle response is instantaneous due to the fact a sensor needs to send a computer the input signals, thus calculate how it needs to be changed, then sent back to the injector and or butterfly valve if it's fly by wire, this all in reality takes nano second's I'm sure to all do? BUT it is a noticeable difference and the dynos don't lie either about fuel injection VS carbs the HP is always a little better on the carbed engine's no matter what it is, doesn't really make sense how a crude mixing valve is capable of creating more power over a computer controlled system??? BUT it's known fact in the engine world, but it's what you gain in ease or startup running and self adjustments, I guess you pay for in a few HP, which really isn't a bad swap....... Very cool Bro, thanks for making this video, never heard of these until now thanks to you, will definitely be checking into one now!

Great upload as always! Repack your silencer, do a video on it while your at it. Mikuni/Keihin use JIS screws, much better than Phillips type.

I’ve been running lectron on a 16 ktm300. It is amazing how awesome it works. I do like the easy adjustability the SC2 provides. Once $ does permit I will try one out. Thanks for the great video.

Good video, there's more info in your video than on the Smart Carb's own channel. Still waiting for a dyno run and some actual numbers from them after 18 months. In Australia, the cost of the SC2 would buy engine upgrades and a tune. Can't wait to go efi 2 stroke on my own bike 👌

A very informative and educational video dude, done in an easy to understand manner! Well done! 🍻🤘💜

I'm curious if this would work for 4 stroke engines as well, or is it possible to make a rack of them for an inline 4 bike. And what about boosted applications?

This type of carb has been around since the early 70's (rod vs needle) BUT they were VERY expensive and almost impossible to tune because a complete stripdown was needed to make any sort of adjustment. I'm glad to see that someone has made it a lot more user friendly because the old type performed extremely well once you had gotten the setup dialed in but the difficulties simply made it a non-starter.

Man, I do not even have bike, yet wached full movie and enjoyed as F..😃 cool stuff this smart carb. And well made movie

Your videos are excellent. Very professional. Nice job !!

Cool video! I'm currently rockin' a Sherco 300 FST trials and it would be so intersting to see how the SC2 would do at a Utah competition with lower revs, lower compression, and slower speeds.

I think this design could be adapted to an automotive application. If I was a designer, I’d start with something like a 2 barrel or 4 barrel design usually seen in a classic American car, since they’re so common.

Thanks for sharing this. I didn't know that it existed. I like that it doesn't have needles, but I wouldn't consider adding it to my fuel injection street bike (if it was possible). I see it much more useful for your type of situation.

Hhawu! Mfwethu. Ilana eMzansi?? Ur channel and presentation is so international...I thought ur like a Texan with his own track in the backyard, just speaking like a Dutch Austrian. Great bro, all the best

That's a crazy price tag to upgrade. I will say the technology is cool, and I'd run it. But not for that much, and they limited to two stroke bikes. They'd have a lot of opportunities to make money on 4 strokes, and ATVs if they got in to it I think. especially people with older warriors and stuff that they no longer produce oem parts for. The aftermarket just isn't as good.

Can I get one for my mower? It's a horizontal Briggs Vanguard 29 hp big block. I mow for a living so more power, better efficiency, cleaner burning would make a big difference in the long haul.

Edelbrock had these years ago called a quicksilver...kind of a pain.. Tons of different rods,and real time tuning was a nightmare. Exact same setup

Edelbrock carbs are like this too. Many people don't like them - I think they are GREAT!!!!!! It's the super pumper carb!!

3:27 fuel filter wrong orientation))) 4:03 - this right)))

Ease of use vs cost is always a big thing especially if your not inclined to learn how to tune/fix your own bike/cars. I have always wanted to try one but can't justify the cost at $1500nzd when i can barely feed myself, i will stick to changing jets and having a cry (although knowing how to read spark plugs and a lambda sensor are handy) Thanks for upload :)

I had a edelbrock carb that functioned the same. Metering rod and a red screw on top.

For single cylinder engines carburetors are superior. Change my mind BRAAAPPPP

But can it work on a old carb motorcycle with no electronics or anything smart like throttle position sensor

If you are sick of stripping Philips screws, it is because those are not Philips screws on that Keihin Carb. They are JIS and a Phillips screwdriver does just that. Excellent video. I would really like to see some actual dyno information though.

So it's basically a SU carb for a motorbike Thats not a bad thing, I did a draw though turbo setup with a SU carb and it worked brilliantly Those style carbs are fantastic

The best way to tell if the carb is correctly tuned is the spark plug. If you want to be on the safe side you can check your spark plug after the first 15min of ride. According to you mixture and gasoline it may need minor changes. We used to do that when go Karting. Remember when it's leaner it goes faster so it may trick you.

When they make advertisment look like a review 😆 Atleast smartcarb finally understod that they need to pay off a few youtubers to keep up with Lectron.

You should have mention the throttle body design, as the conventional flap/butterfly design doesn't provide a linear curve of intake air (air being swallowed by the engine), it is more like a quadratic one, which you remove almost the whole air restriction at less than 90 degrees opening. This new design provides an exact intake area (because it is like a slider gate), so at 100% opening throttle body, you'll have 100% of the area available to suck air. Not that i have one or even tested it, but just by how it looks, it seems to me that provides an exact AFR the whole time, after a proper calibration of course.

Thanks for taking us along on your journey. Good trouble shooting and wise to seek advice like you did. 💪👍

Thanks to Smart Carb for explaining the differences between SC2 and SU carbs. I was completely wrong. A "superior SC2" metering rod is in no way like an SU metering needle with one side machined off. The SC2 has a flat slide raised by the throttle cable and the SU has a cylindrical slide raised by the vacuum in the venturi. Again; no similarity. The SC2 has an integrated float bowl and SU only used this from 1972. AND the SC2 passes EPA tier2 emissions on PER MILE on 4 strokes. This is obviously very difficult for a small bike compared to a 90's small car. Congratulations. Dave D

I just want to thank you for doing this video. I’ve been in the market for a carburetor for a while, and I was not sold on lectron. I’m definitely going to contact smart carb😎

The smartcarb looks really nice and clean. Imagine having it in a CR 500 :D

Just on the surface, it looks like the old air valve carburetor design, such as SU carbs that were used on many vintage European and Japanese performance cars and roadsters. There's a damper chamber filled with fluid (light oil) that delays the rise of the air piston when the throttle is opened, hence eliminating the need for a power jet. The main jet has a tapered needle that admits more or less fuel depending on the throttle pressure. The type of fluid used in the damper chamber is an area for exploration and one of my favorites was brake fluid....

I'm wondering if they do smart carbs for cruisers. I'm always looking for a way to get better gas mileage. An helping the environment even if just a little is a good thing in my book

This is beautiful. I love building mini bikes and go karts out of Predator and other small generator engines. This could be a game changer for us since we dont need to need to worry about jets or such. This is a fantastic product.

I want four for my Nissan truck now. Best yt video this year. Probably.

Imagine adding individual circuits so you can tune each one independently... "no jets" is just a word play. Jetting refers to fueling - and the other carbs using no jets also requiring fueling adjustments.

Im retired bike mech and prefer carbs way above fuel injection . Simpler, cheaper , way easier to fix and more reliable and above all it gives you full performance. No need for mappings and that sort of crap. Once jetted and tuned correctly it remains tuned. Bottom line , I'll choose carbs 10 times out or 10.

Im def a Keihin guy. I pretty much try to leave the idle and air/screw in the same spot and might go down a jet smaller in summer (less dense air makes it run rich) and one size up in jet in the winter. My bike came extremely rich from the guy I bought it from since he was at much less elevation than I am. I felt like a king that ive learned how to tune my Keihin.

700$ for a carb. No thanks.

@ 0:31 Man says to smart speaker," computer, when is a good day to ride?" The smart speaker replied," everyday is a good day to ride." LMAO, I love that clip scene. 😂

While this seems like a cool adjustable carb I didn't see any features that could even remotely classify this as a "smart carb". I was really hoping for a smart carb that could automatically adjust like we have come to expect from their fuel injecting counterparts. A "Smart Carb" should include pressure and temperature sensors for intake and atmospheric conditions as well as a micro processer to monitor/calculate optimal settings and a stepper motor to adjust the screw position accordingly. Maybe a better name for the product would be "Easy Adjust Carb 2 (EAC2)"...

I thought this would be some complex electronically controlled doodad, but that's actually super simple and ingenious. Would love to have one for my Vespacar but... that probably needs some custom adapter and such. Also just bought the car so need to save up a little first haha. I guess I should contact them and see what's possible once I got the funds.

wow, you can buy a used bike for the price of that... I was thinking around $250 usd, but its in the $700+ range.... At $250 usd it would be reasonable.

Yep…I’m getting one. For my 2023 Beta 300RR!

It's a lazy man's electron carburetor with all the fun taken out of it of manually adjusting that tapered needle one notch at a time and then when running out of notches you grab into your drawer of a thousand other needles of different tapers and start all over again but you guys have taken all the fun out of it I say by merely pushing a button what fun is that ⁉️ it will only lead to more time on your hands to turn the throttle and wear out your engine completely wfo throwing roost at your buddies pissing them off to the point you will have no friends... As you will be riding while they are still at home changing Jets

I put one a a motorized bicycle I built back when I was high school and dude these carbs don’t play best $700 I’ve every spent on a motor mod.

At 3:33.. I want the fuel filter the other way, so i can see the dirt build up. Even white plastic shows how dirt builds up inside. Its easy to forget fuel filters, even if they are easy to change.

Can it fit on a 4 stroke street bike tho?

Idk about the bolt argument. I spent a bit as a mechanic and small hex keyed bolts strip out just as bad or even worse than phillips screw heads in my experience. This can be mitigated by having a really high quality hex socket, I recommend Snap-On for the best, but yeah... They strip out really easily if it's torqued down even a bit over spec.

Okay Okay I'm half way through the video and I already see the genius simplicity in this carburetor. I love it!!! *EDIT* alright I made it all the way through the video. Finally I find someone that see the low fuel consumption rate to be more environmentally friendly! Thank you!

It's a detailed 👌 examination practically without any compromise. Well done for informative education.

Is it only for dirtbikes? Would be awesome on my aprilia rs 125 :D

Dude! Your US accent is so good! If it wasn't for that Dacia Logan Pick-up thing made by Lada, I would have never guessed you're russian.

It looks to good to be true…too simple to work…but I bet cavemen thought that when someone invented the wheel! I’ve visited the website and asked the question if it would fit a 2003 Aprilia RS125 running a 34mm dell’orto carb without a throttle positioning sensor. Will report back their response.

i have had a SC2 and i didn't notice any fuel savings at all and it just works like a normal carb but with a gimick. it's not really worth the money just stick with a traditional carb or convert to EFi. don't get me wrong it still works just fine but i didn't notice any difference in any aspect it just ran like a ran like a normal carb.

very cool vid, in my shifter kart road racing days, i did use the needle alot when tuning, i like this design

a helpful tip: we often think of things llike mpg and equate this to we need more gallons to make more power, what is confusing about this is we don't burn gasoline....say it again, we don't burn gasoline. we burn air and gasoline is the catalyst that makes it possible. so if you have a fuel air ratio of 25:1 than you burn 25 parts of oxygen to 1 part gasoline. also i am not saying 25:1 is your fuel air ratio, its just an example. also this carb could be a great thing if you like old bikes like i do.

they should get models for generators, power equipment, and ATVs-!!! i would invest then!! for my other carb engines that i depend on! these guys sound awesome

The Sonex aircraft I flew for 18 years had an aerocarb they sold that I installed and it worked the same as this carb. I loved it because I could adjust the mixture to go lean of peak at high altitude.

It means that a smart carburator needs a smarter machanic to install and set it up.

hey, i think the fuel filter is in the wrong direction, cause the "bigger" end, must go to the carburetor... But cool Video! I was not aware, that this smart carb's are exist! Top!👍👌

Your so very detailed explanation using mathematical figures are very impressive indeed. But for people on the street like me, we need the following simple explanations : is it more economical n longer lasting n more trouble free ? Could you just concentrate on these 3 issues ?

I had a yz 490 air cooled two stroke in the 90s it was an 84, and it was a monster.

Ya need to learn how to read your spark plug in order to fine tune.

Very concise overview. You're doing well to sell me a Smartcarb with no BS! Love the production value and editing on your videos.

I've seen what is considered a "smart carburetor". It used a AFR sensor, air bleed valve, and a computer monitoring and adjusting off the AFR.

My brother got one for his ktm 300. He's pretty happy with it

Wish they made one of these for my 1953 VW 1.5l motor. Would really make my little kit car come to life.

It looks a lot like the old sidedraft carb you saw on old english cars, SU type. On those, you can change the metering rods and adjust them up and down as well.

I know nothing about this carb but I know a lectron carb on my yz250x was a god send. Hands down the best add on you can do to any 2 stroke.

I ran X-tra rich! As long as I wasn't fouling plugs at WOT! Pre-mix = compression! Compression = Hp with 2-strokes😊!!

the fuel savings alone would make this type of carb interesting to many. Consider when racing you could potentially run a smaller tank. saving weight. of if you were enduro riding, you could ride further between fill ups... and over all, you would be saving money on fuel.