Author Topic: STIC metering block for Keihin Carbs...my personal experience  (Read 955 times)

Sfade

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It's not on my 4t Sherco obviously, but is on my 19' KTM 250XC with Keihin and will apply to anyone with 38 or 36mm Keihin carb...ie Sherco 2ts.  1st and foremost I am doing this on my own accord and have no ties to the company or inventor George Boswell.  He's a good guy and responds quickly to questions and great customer service/support.  He does however self promote a bit too much on ktmtalk. 

If you don't know what STIC is, its a metering block to replace your Keihin one--a very nicely machined CNC one at that.  You can search online and learn all about the dynamics if you want, but basically it claims to provide a lot of torque and power.  After you buy the STIC and JD jet kit for it you're looking at ~$450ish I think. 

Your ideas of how jetting works will need to change.  My current setup is 195 Main, 50 pilot, and JD red clip 4, Airscrew 3.5-4 turns out.  Very different and even sounds and feels different.  It's a set and forget jetting that supposedly self adjusts for altitude and temp for the most part which is nice. 

 I was against it at first and thought the gains couldn't be worth the money especially after buying and RK Tek head and Keihin for my KTM.  I stripped my pilot jet like and idiot so instead of buying a stock metering block I'd just go for it and try the STIC out hearing some swear by it....curiosity got me.   

Does it work and is it worth the money is what you want to know?  Hell yes it is!  Its good, I mean really good.  For example a rocky loose very steep hill usually required 2nd gear and feather the clutch to keep from spinning/stalling with stock Keihin/RK.  With the STIC I don't even really touch the clutch.  I can let the RPM drop almost to nill and it keeps tractoring.  I can run a gear higher and still loft front with a snap.  The pull is very impressive.  The transition is a tad more linear into the mid/powerband and its a rocket and pulls really hard.  The overrev is insane--it just keeps going and going.  Gas mileage is about the same.  I let a friend ride it and he wants to sell his TPI and get a carbed bike just to put a STIC on it.  I said get a 2021 Sherco and slap it on. 

Along with the RK and Keihin, best mod I've done.  Tokyoffroad on youtube is a smart engineer type that has reviewed the STIC in depth.  Not an expert on it, but happy to answer any questions I can about it. 
2021 Sherco 300 SE Factory
2020 Sherco 300 SEF Factory (Supermoto)
2019 KTM 250XC

erdat

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Re: STIC metering block for Keihin Carbs...my personal experience
« Reply #1 on: June 23, 2020, 10:31:51 AM »
Thank you for taking the time to share your experience. I am sure that many of us have read about it, but to here it from an actual user is always good.
'15 SE-R 250
Ankara, Turkey

EnduroMD

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Re: STIC metering block for Keihin Carbs...my personal experience
« Reply #2 on: June 24, 2020, 04:56:58 AM »
Thanks for the detailed report! I have a Lectron on my KTM 200 but was curious about the STIC performance. I am tempted!  ;D
2019 Sherco SE Factory
2013/2015 KTM 200 (linkage)
2012 KTM 150 Son's bike
Goshen, Indiana, USA

Sfade

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Re: STIC metering block for Keihin Carbs...my personal experience
« Reply #3 on: June 27, 2020, 06:34:55 AM »
If I had to buy another 2T, it would be a Sherco 250 with a STIC.  Now that KTM is TPI just not a fan.  Rode one and no comparison to a keihin/stic combo.  That and I had to spend some coin to my suspension the way I wanted on my KTM.  Sherco KYB stock is prefect for me once I took 20cc oil out. 
2021 Sherco 300 SE Factory
2020 Sherco 300 SEF Factory (Supermoto)
2019 KTM 250XC

stic fuel systems

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Re: STIC metering block for Keihin Carbs...my personal experience
« Reply #4 on: April 10, 2021, 08:35:04 AM »
Newsletter #425

STIC development, STIC followed the recipe for success!

¶ 1 The development of the STIC was engineered to perform a multitude of new proven concepts that work in harmony based on its inventive “Auto Sensing,” “Auto Selection,” and “Auto Acceleration” features; it was not a guess in the dark, it was designed to do what it does.

¶ 2 The STIC represents +60-years of experience in building high-performance racing carburetion systems in carburetors including Weber, Dellorto, Holley, Rochester, Mikuni, Keihin, and others. The STIC invention is a new patent filed in 2012/2013 and issued during 2019; we just now (April 2021); received “notice of allowance” on a STIC divisional patent that further solidifies the technology, applying it to other areas. Go figure, eh!

¶ 3 The STIC methodology is counter-intuitive to conventional carburetion thinking (a change in a paradigm); however, it involves real world verified physic principles (the dark side of little understood facts) that were deigned to work in harmony. The STIC total concept was developed in secrecy over a period of years without the use of dynamometer testing, consisting of real-world field tests; meaning real world field testing that proved various circuits worked as stand-alone passages. Previous STIC carburetor modifications were restricted to retrofitting existing carburetors by precisely placing control circuits into existing metering systems as well as minute body modifications. During the mid-nineties, STIC looked at the possibility of modifying the Mikuni and PWK Keihin A/S carburetor. It was determined that the Mikuni and Keihin metering block did not have suitable structural design or thickness to insert a jet tube and to provide the STIC connective passages necessary to gain the performance that the STIC was capable of. It is important to note that the STIC original design has not changed from its original design. We have only made dimensional changes (passages) in the internal passage sizes to accommodate a multitude of engines operating through a very broad spectrum of conditions. In other words, it works on everything from the 125cc through 500cc two-stroke, including the four-stroke!

¶ 4 Modifying Mikuni’s goes back to the 90’s, however, this was not with the STIC concept, the actual bodies were modified with air correction jets, contoured inlet to a uniformed shape. They were very effective in wining several championships. The Keihin and Mikuni did not have suitable structure to modify, a majority of them had fixed orifices in the metering system and the castings were very thin, requiring epoxy if you wanted to change the structure. During 2014, the inventor determined the Mikuni was more difficult to make the block for it.

How it all started (The STIC total process):

¶ 5 An old customer from the 90’s asked the inventor; “…do you think you could modify the Keihin Air Striker carburetor….?” I asked him to send the carburetor that he wanted modified. When it arrived and after careful review, it was determined that it could not be modified. However, it may be possible to make a replaceable metering block. With that being said, the Inventor decided to make a completely new metering block to replace the Keihin A/S OEM stock block. The inventor designed the STIC metering block and the STIC tube from the ground up. This design, testing, and manufacturing of the prototypes consumed the time from 2012 through 2015. The blocks are made of aircraft quality 6061 Billet aluminum; they are machined on CNC equipment to ensure durability with repeatability. This would also involve designing a new STIC brass jet tube to replace the Keihin fixed orifice the tube is made of a harder corrosion resistant Marine Brass. At the same time, the inventor wanted to have a STIC specific gasket that would be gasoline, ethanol, and two-stroke oil resistant; it would have better sealing and durability; the new STIC block gasket is slightly oblong in its cross-section area and is made of a Cri-Seal Silicone.

¶ 6 Since that time, certain tube core measurements were determined through field testing. These sizes were finalized and were dependent on field testing and the availability of tuning parts such as the needles and slides. Fortunately, James from JD Jetting supplied a Red (II II), Blue (IIII)), and a totally new White needle (III I) as a replacement. The difficult to find Yamaha and Suzuki needles in numbers that were sufficient to meet demand for the STIC. Yes, the STIC is a New invention, it is counter-intuitive to conventional carburetion; be prepared to learn new things.

¶ 7 Rather than make false blue sky promises, snake oil claims, and empty promises, I wanted to let it prove itself with the persons testing the STIC; these are individuals on their own free will; they discovered that the STIC works as planned and represents a change in the way we think about how things work. The STIC works well and is documented by trusted end user individuals with integrity such as you the public. No one has been paid to give their opinion that would favor STIC; their opinions are free will; thank you for your excitement and your willingness to read opinions and to make your own decisions. Ultimately, you will find this invention to be a break-through in fuel system metering. The STIC circuits (passages); have unique individual features that are designed to work in harmony with each other; they have been tested as standalone passages to determine their sizes.

¶ 8 When it comes to an understanding the mechanics of how the Internal Combustion Engine (ICE) intake, combustion chamber, and exhaust system process and carburetors work; remember, millions of individuals, engineers, and scientist over the past 100-years accepted the fact that the past calculations, predictions were correct; this is the way it works, and we cannot do anything about it! They gave up on combustion efficiency and carburetion; they went around the problems that seemed to be incalculable. The industry resorted to using computers, close-loop sensors, and turbo-super chargers however, they left a lot on the table.

¶ 9 There are some individuals such as yourself and others that question how things work and that is a great trait, as there are new things to discover. For those that are willing to learn from others and the past discoveries, there are great opportunities for those willing to learn. As we continue our search for new discoveries; stop to think for a minute; every day in the real world; we see miraculous discoveries and transitions from molecules and atoms that occur at ambient temperatures and regular pressures; even in our own bodies. Often it is just finding the correct recipe; (“… an order of events that must be followed …”) — before simple ingredients turn out to be the best cake ever; aka the STIC is one of the best fuel systems.