Italianiron & Britiron Classics Love our SmartCarb Flat-Slides

Posted by Scot Wilson on

I am very excited at all of the interest in our use of SmartCarb2 flat-slide carbs on our different 4-stroke Ducati vintage and modern twin cylinder engines. After having significant success with the use of the original SmartCarb flat-slides, we became dealers for the brand. The value proposition shared by the company is what we have been able to confirm with our different vintage and modern 4-stroke Ducati 2 and 3 valve engines. At, we have been able to confirm the factory's claims of the technical benefits of the SmartCarbs as being a 30% saving in fuel consumption6 to 14% improvement in HP, adaptability to altitude and other atmospheric changes, ease of adjustment and 80% less hydrocarbon emissions. We have also found that once we have set our SmartCarb2's, there has been no need to fiddle with settings. Also worthy of note is the "real-world" benefit experienced riding up and down our mountain roads with no impact to our Ducati 900 ss MHR (shown above) maintaining linear power delivery. There was also no need to adjust these carbs at different elevations as they are self-adjusting. SC2's are truly remarkable!! 


These SmartCarb2's represent the pinnacle of technological advancements in fuel delivery systems. As such, many of the tuning issues and questions that we get just do not pertain to the SmartCarb2 series. As mentioned in one of my 11 blog posts covering our research and analysis in using the SC2's, I have relayed that using the SC2 is like using a more effective form of "fuel injection" and without the cost. Yet, I continue to get asked questions about why Technology Elevated, the manufacturer of the SmartCarb2 is primarily known in the 2-stroke and dirt bike world. The fact that the SC2 is so successful in the 2-stroke world further supports my position that the 4-stroke Ducati engines benefit from this SC2 technology. However, whether discussing a 2 or 4 stroke operating principal, fueling requirements are almost entirely dependent on the performance level desired of the engine. A two stroke engine uses the crankcase as an induction pump and as such it does not have as clearly defined intake volume as it is variable due to piston movement. Four strokes, contrarily, have a fixed intake volume and in this respect are usually able to “trap” the intake charge with less chance for fuel mixture losses. In this way, the 4-Stroke engines have a more clearly defined intake process for greater efficiency and will benefit more significantly to the precision of the SC2.

Due in part to the pressurized float bowl, the SmartCarb2's have been proven capable of keeping up with the steady, but variable demands of a 2-stroke engine that is firing on every stroke. After our analysis, we have found that our 4-stroke Ducati engines with their clearly defined intake process have been operating more precisely with these flat-slide carbs. SmartCarb2's are also used successfully in marine engines, snowmobile engines, and ATV's. The new generation of SmartCarb2's provides the same unmatched performance gains enjoyed by thousands of customers with different applications in over 80 countries worldwide. At we contend that this series of fuel delivery systems represents the most accessible, "plug-and-play" format in the industry. Additionally, for those of you who are concerned about how much space that you have to mount a single or dual SC2, please find a dimensional reference that demonstrate the factory's efforts to improve fitment for your application. The updated SC2 can now use nearly all stock throttle cables and offer other enhancements, such as, greater accessibility to the float bowl drain screw for servicing and plumbing of fuel lines.  

We are also excited to introduce our billet 28 mm SC2 SmartCarbs that are designed firstly to replace conventional spigot mount top-pull carburetors in 2-stroke applications and will fit most intake manifolds and conventional air boxes that use Keihin PWK 28mm or Mikuni VM 24mm and 26mm carburetors. In addition, we are find that these smaller units are ideal for use with smaller displacement engines such as the early Ducati single cylinder bevel drive engines that have a significant following worldwide. I continue to be a big believer in maintaining the least amount of "turbulence" or disruption in the flow of the fuel mixture. That comes from effectively matching the same size of the inlet port of your engine, manifold used with the size of the venturi of the SC2 that you chose. 


We are very excited at the potential of the SmartCarb2 in bringing reliability and performance enhancements to our vintage British racers such as our Norton Commando's, Atlas, Dominator's, as well as other British marques. It is my plan to get my Norton 850 JPN up on her feet shortly and we will be using a single 36 mm SmartCarb2 in our application. Will post dyno results once we have the bike up and running. The value proposition of the SmartCarb2's as stated by engineers at Technology Elevated are:

Performance Guarantees

  • Ride Faster | 10% more power size-for-size
  • Ride Farther | 25-30% greater fuel economy on average
  • Crisp, clean, linear throttle response bottom to top!

Tuning/Ease of Use

  • External adjustability by hand, in seconds (no tools required)
  • Complete air density compensation (consistent air/fuel ratios at any elevation or temperature)
  • Accepts all modern stock throttle cables
  • Single circuit design (NO Jets!)
  • Set it and forget it!


At BritIron Classics, we continue to offer quality OEM and newly manufactured engine and chassis bits for ManxCommandoAtlas, Dominator, Vincent and Seeley road and racing motorcycles. As mentioned before, I am currently working updating our listings in British Pounds Sterling as well as in US Dollars. Please contact me with any currency questions. A new "Make An Offer" feature is currently available for our used OEM Ducati and Norton items only. As a result of our offerings, it is our hope to help you to become immersed in the history, the passion and the early technology of these amazing machines. Let us "Fuel Your Race Passions" to keep the sport of Vintage Motorcycle Racing alive and well!!

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  • Hi my name is Stefan and live in Melbourne Australia .I am building a Kawasaki KLR650 round the world motorbike with stock 2012 motor and staintune exhaust.Has the Smart carb been fitted to such a motorcycle?Can you put me in contact with any people in Australia that can share their experience with the Smart carb.Any advice is appreciated, Cheers.
    Stefan Dopke on
  • I too have a 1974 Norton Commando 850 MkII Interstate that I have owned and ridden since i bought it new. It was refurbished from the frame up in 2012 including a pair of 30mm PWK carbs. Vast improvement over the original Amal carbs, but still don’t like changing altitudes much, though not as bad as the Amals were. I’m wondering if changing to a single sc2 as per your John Player Norton would fix even that last little annoyance? Please let us know what your results for that experiment were.

    Tim Jones on
  • I’m interested in SmartCarb options for my mkII 850 commando
    Currently have a pair of FCR35 Keihins
    Please advise.
    BTW – I’m in Australia – do you ship to here?

    Rob Craig on

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