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June 14, 2019

Subject: STIC new air screw spring:

When using the STIC metering block; once it is in the proper jetting window; it is easy to maintain with minor air screw adjustments. If you resort to the standard way of jetting you may experience lean or rich conditions at the zero to ¼ throttle position; the STIC metering process is totally new; never invented before now. This new STIC concept requires a new way of thinking (a change in a paradigm). The STIC main jet tube circuit and the pilot jet are now married (connected) together; causing them to be multi-functional. In fact, they operate at the same time all the time. For most of the engine sizes 250/300; this requires changing the main jet to 182 to 195 and adjusting the front air screw setting at 3 to 4 turns out. The larger pilot jet is part of the power system and should remain in the 48/52 range. Setting the air screw to the larger settings will siphon-break the larger pilot jet as well as the larger main jet. STIC now ships with a new longer stainless spring; (new: .562” versus stock: .453”).
 

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June 14, 2019

Subject: STIC new air screw spring:

When using the STIC metering block; once it is in the proper jetting window; it is easy to maintain with minor air screw adjustments. If you resort to the standard way of jetting you may experience lean or rich conditions at the zero to ¼ throttle position; the STIC metering process is totally new; never invented before now. This new STIC concept requires a new way of thinking (a change in a paradigm). The STIC main jet tube circuit and the pilot jet are now married (connected) together; causing them to be multi-functional. In fact, they operate at the same time all the time. For most of the engine sizes 250/300; this requires changing the main jet to 182 to 195 and adjusting the front air screw setting at 3 to 4 turns out. The larger pilot jet is part of the power system and should remain in the 48/52 range. Setting the air screw to the larger settings will siphon-break the larger pilot jet as well as the larger main jet. STIC now ships with a new longer stainless spring; (new: .562” versus stock: .453”).
JD Jetting has made some really great dyno diagnosis of the STIC metering block on KTM TALK. What we are really seeing; the STIC is doing something very different to the air fuel mixture. In the future STIC EFI adapters; the injector replaces the main jet and the injector injects into the STIC processor.

http://ktmtalk.com/showthread.php?545649-STIC-jetting-thread/page37&highlight=STIC+metering+Block
 

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Since there are several individuals that are physics experts; perhaps this explanation and analogy will perhaps bring some light to deeper physics; there are no rule changes; this is how the STIC works.

Consider how planes manage to fly at 35,000 feet; with the atmospheric pressure being 3.47 psi (inches of HG 7.06) on both sides of the wing and the plane weighs over 20 tons? In fact, air speed is removing the pressure from above the wing creating a greater lift (difference in pressure) by airspeed; with lesser airspeed the plane would drop out of the air. As the air moves over the wing’s upper airfoil the speed increases at the airfoil apex.

The point being at 35,000 feet there is no vacuum; although, anything less than atmospheric is a partial vacuum according to earth scientific standards. Thus, the plane's flight and the lift are based on creating a shearing differential pressure drop across the wings surface based on air speed. This is the principle that the STIC’s differential pressure drops are based on (air and fuel mixture speed).

Air and liquid speed pressure drops can be equated to a simple spray bottle; blowing air across an opening does remove the pressure above the liquid to in fact remove the pressure to cause a vaporous mixture above the wet level and toward the spray outlet (aka the STIC tube outlet). For liquids that are more unstable such as perfumes (emulsified air/fuels); the spray bottle can deliver a more vaporous mixture. The same can be said for the STIC methodology with its numerous adiabatic pressure (pressure) drop features (passages); they cause the fuel to merge with the ambient oxygen and to be forced into the adiabatic passages to bring a more vaporous emulsified mixture to the carburetor outlet independent of engine suction. Although engine suction induction is necessary for a normally aspirated engine; this explains how the STIC process increases vaporization by speed and works in harmony with the engine’s induction process. Ultimately the last extreme pressure drops occurs at the STIC tube outlet as it expands into the carburetor bore.

https://en.wikipedia.org/wiki/Speed_of_sound


https://thumpertalk.com/forums/topic/1296436-stic-super-vapor-test/
 

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I’m not that fussed on physics and have not read all the Stic info on any of the online threads but I am wondering why we need to all be seeing so much duplication of the threads? It’s the same stuff? It’s on two threads here and similar on KTMTalk. Can it be distilled into one main thread per forum or does every question need the same answer posting on every forum thread?

Just asking but probably won’t see the reply.
 

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I’m not that fussed on physics and have not read all the Stic info on any of the online threads but I am wondering why we need to all be seeing so much duplication of the threads? It’s the same stuff? It’s on two threads here and similar on KTMTalk. Can it be distilled into one main thread per forum or does every question need the same answer posting on every forum thread?

Just asking but probably won’t see the reply.

Its keeping the forum alive man..... Embrace it ?‍♂
 

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I’m not that fussed on physics and have not read all the Stic info on any of the online threads but I am wondering why we need to all be seeing so much duplication of the threads? It’s the same stuff? It’s on two threads here and similar on KTMTalk. Can it be distilled into one main thread per forum or does every question need the same answer posting on every forum thread?

Just asking but probably won’t see the reply.
I agree, I started my thread because I wanted my experience with using and setting up the STIC block to run in its own thread, you are right though, there is a lot of duplicate posts flying about.

BTW, I'm still working on a couple of setups.
 

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I’m not that fussed on physics and have not read all the Stic info on any of the online threads but I am wondering why we need to all be seeing so much duplication of the threads? It’s the same stuff? It’s on two threads here and similar on KTMTalk. Can it be distilled into one main thread per forum or does every question need the same answer posting on every forum thread?

Just asking but probably won’t see the reply.
[/B]Pindie; thanks for your response; I receive many requests each day in how it works. Sorry to be repetitive; however, there are many new people reviewing these forums each day. Some do not understand deeper physics. If engineers and designers knew some of the things I know they would not have left so much on the floor and left the door open for improvements. Although I could really get technical I have decided to use analogies to explain things in the real world. Designing intricate fuel and air circuits requires a degree of experience as some passages are incalculable in terms of measuring a value. If you read Professor Gordon Blair's and Taylor's books (sorry to report both have died recently; Blair and Taylor from MIT are considered to be the great engine gurus of the world; both with incredible knowledge); you will understand that fluctuating engine dynamics make design somewhat incalculable; he mentioned those very issues in his last book.
 

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STIC-TIP:


STIC-TIP # 1: Pilot jet is now multifunctional while using the STIC; it now: (1): provides idle and air fuel. (2): is now part of the STIC power system providing additional fuel and air to the main circuit outlet from off idle to full main. STIC pilot should be in the 48/52 size range due to multifunction.

STIC-TIP # 2: The main jet tube during idle now provides vaporous-mixture to the idle intermediate passages.



STIC-TIP # 3: Float level must be correct factory level up to 1/8” lower. This is to prevent running rich.



STIC-TIP # 4: inspect the float needle valve; replace each year, or sooner if it is damaged.



STIC-TIP # 5: Most Keihin carburetors will require a small plastic shim under the E-Clip to prevent the needle from vibrating causing excessive wear and to provide a consistent mixture of the air and fuel



STIC-TIP # 6: Longer air screw spring must be used when using the STIC metering block due to needing to have the air screw setting in the 3 to 4 turns out. These new longer corrosion resistant-steel springs (.100” longer) now come with the STIC Block. They are available no charge; contact STIC. ​
 

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STIC tuning instructions.

The STIC has been tested all over the world for the last seven years; ranging from sea level to +9,000 feet; with dramatic changes in temperature; without requiring any major adjustments. Here is a fact; the STIC will work with jets, ranging from 178 to 220; the preferred setting for maximum performance will be in the 190 to 210 range; this applies to the 125 to 500cc engines. The pilot jet must be at the +50 range with the 50 being the best overall (this is part of the power jet system). The air screw must be in the range of 3 to 4 turns out. New Keihin STIC carburetors have the new longer (+.100”), stronger piano-steel spring; so, no worry about the air screw working loose. These new springs are available from TOKYO, Harris, and STIC factory. If STIC adjustments are needed; first work with the needle clip position, top clip will make the mixture leaner, the bottom clip will make it richer. Adjust accordingly to your preference. It is my estimation that one must use a needle with the top straight section being at least. +. 106" in diameter; this starts with the JD red (+.106"), ranging to JD red II; the Yamaha N3EJ at .107.5" and the Suzuki NEDK needle ranging up to +. 108."

Next, adjust the front air screw in small increments; not going below 3 turns; this larger air screw setting air corrects the larger pilot jet and allows more air to go into the main jet outlet. As I mentioned be sure to check for clean air filter, check the reed cage for any petal wear. Do not run the vent lines into the air box; this will cause the carburetor to run lean.

Even though others may disagree; the engine should be warm before attempting any STIC jetting decisions. Believe it or not; oil and fuel can and do accumulate in the case and transfers. When installing the STIC metering system; here is my advice; install a new spark plug and run STIC for at least 30 minutes at various speeds to help clear the case and the engine of any raw fuel left from the previous carburetor.

In summary, do not be lured into using a smaller pilot and main jet; there is a substantial increase in power by using the larger jets. The STIC is heavily emulsified with air and other forces; using the smaller main jet will tempt you into making corrections in the wrong manner. The STIC has a multiplying (increasing) fuel curve, an instant power system. The STIC is a new process and requires learning new things; enjoy. Feel free to contact STIC headquarters for any assistance and upgrades; glad to help and answer any questions.
 

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I’m not that fussed on physics and have not read all the Stic info on any of the online threads but I am wondering why we need to all be seeing so much duplication of the threads? It’s the same stuff? It’s on two threads here and similar on KTMTalk. Can it be distilled into one main thread per forum or does every question need the same answer posting on every forum thread?

Just asking but probably won’t see the reply.
As you may know we have young kids coming up from the 65 and 85cc bikes; we always have new people coming on board that my not have the knowledge that you have. I am now 77-years old and want to share what I have learned over the last 60-years. It is not meant to be repetitive; however I think it is important to reveal to the new readers and the younger generation.
 

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Historically STIC tube research has been ongoing since its inception. We have tested in .010 increments ranging from .111 to .116. Due to the STIC acceleration and power system being so aggressive (planned features); this has resulted in selecting needles that have a greater upper straight section diameter to tame the STIC system down. With the needles being limited in their thickness; I have decided to provide a taming passage process (the planned additional emulsion hole). Further we have reduced the STIC Jet tube outlet to 2.870mm; this is down from 2.910mm. Our current testing conducted by TOKYO Off-Road and others is very favorable; with improved acceleration, greater power, and cleaner on the bottom. For those that have the older units they will be replaced free with you paying the shipping; you must send the entire block with tube and or the entire carburetor. The replacement tubes will not be sent out alone; you must send the entire block with tube and or the entire carburetor. STIC headquarters will make the installation at no charge.
 

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This is a 113A; different than a standard 113 and 114; I left room for this upgrade; it is because of testers like you that were not satisfied with the STIC Jet Tube and having to resort to larger homemade needle that would not be practical for everyone. Its all about advancing the STIC process to have a user friendly product; that does not require substantial tuning to make it work. This is nothing against anyone that has used the product and complained about the richness; we listen and have acted appropriately to make corrections . As I said the upgrades are at no charge to those that have the other previous units. We heard that it was rich on the bottom from several persons; not just you. As we make improvements we will upgrade anyone that has one. I am asking those that have the earlier models to return the complete block and tube to me and I will upgrade them at no charge.
 

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sidecarbod; thanks for your posting; here are the details for replacement with the new 2.870mm "A" series tube

Field testing of the new 2.870mm "A" series STIC Tube is positive making the system run cleaner on the bottom with even greater acceleration. This tube is designed to improve and reduce the low end richness; to replace the tubes you may have at no charge; contact STIC Headquarters at [email protected]
https://www.youtube.com/watch?v=8Fv7HLmvI7s&t=304s
 

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STIC metering block Jetting upgrade: New 2.870mm and 2.890mm STIC jet tubes will be available September 5, 2019; these improve the low-end richness and provide greater fuel flow at the upper RPMs. The new JD Jetting kit for the STIC metering block offers a new JD Jetting STIC kit that fits the 125 through 300cc. The STIC kit will include two needles (JD Red/Blue II-II) with the small tapered tip; approximately .055” — these have a larger straight section with one being smaller than the other. The JD jetting kit for the STIC will come with a jetting selection that will allow you to jet the STIC block from the 125/150 thru the 300cc. The carburetors coming from STIC and its dealer/distributors will have the JD kit as an option. Call JD Jetting for details and the JD Jetting STIC Kits. There is no need to file the needle tip; these JD needles are tapered to the .055” tip dimensions.
 

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In the STIC metering block upgrade; we remove the block washer; we check the length of the tube passage to make sure it is correct; we check the crossover passage for alignment, and it important that the tube is installed in the correct procedure. There is no difference in cost in sending the complete block versus just sending the tube. We will replace the tube at no cost to the end user. There are a lot of older test units out there and we want to remove those from the system with the latest version.
 

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Thanks: Mark (TOKYO Off-Road), Derek (Harris Performance), Sidecarbod, Sand300, and others; thanks for your dedication to finding the elaborate inner workings (intricacies) of the STIC metering block. The STIC metering system is a sophisticated intricate metering process designed for all-out performance. Over the past few years others including me, have sought to tame the system down with more ridable finesse for demanding trial riders. The original design was all-out motocross with instant torque and acceleration with a progressive ever-increasing vaporous fuel flow rate without the addition of wings and power jets. Thanks to James from JD jetting for his dyno and field testing; we now have a STIC High Performance jet kit. This consist of two needles with .055” tips;(one richer (Blue) at the top and one leaner (Red) at the top; a selection of jets from 180 to 200; an additional pilot jet; longer Air Screw with longer, stronger spring (coated steel piano wire) and Jetting instructions. Although we have systems that have run from sea level to 12,00 feet (video available soon “Big Bertha” Colorado, third gear; with same jetting); this was a 300 KTM and the only one out of 10-riders that day to complete the hill climb. We have riders with more sensitive jetting requirements; thus, we have jetting recommendation for the higher altitudes. JD, Mark (TOKYO Off-Road), and others have successfully utilized same jetting at Sea-level to +6,000 feet with no need to re- jet. STIC now offers free replacement of the existing .114” and .115” metering block assemblies. For free replacement; you must send to STIC Headquarters and it must be the complete block with tube. When we receive your STIC part; we will make necessary upgrades to the block (for the older units out there) and we will install the new STIC tube. If you elect to send the complete carburetor, we will check all settings, including the float level; will install stronger longer air screw spring all for No Charge. The new STIC tubes are now available on exchange basis only. As of September 10, 2019, all new STIC metering blocks will come with the new “A” series tube.
 

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STIC instructions with JD Jetting.

For maximum performance; the new JD Jetting kit for the STIC metering Block is highly recommended. The STIC tuning kit for the STIC Metering block; is available from STIC headquarters ([email protected]); MB*DBB-Performance; Harris performance (Derek);TOKYO Off-Road, and JD Jetting. This STIC kit has been engineered by James, the founder of JD Jetting; take his advice. The kit includes the following: main jets, (180 to 200), pilot jet #50, new longer stronger spring; two needles; Red II-II; leaner top, Blue IIII, richer top) — both have a smaller tapered tip (approx. .055”).

For the last seven years the STIC has been field and dyno tested all over the world; ranging from sea level to +9,000 fee. Dramatic changes in temperature and elevation do not require any major adjustments. If you have an earlier model STIC; there is a new free STIC Tube upgrade; you must send the entire block and tube to STIC Headquarters. Send the STIC metering block and tube directly to STIC Headquarters for free tube upgrade. If you want everything checked including proper float level; send the entire carburetor with slide to STIC headquarters (no charge).

The STIC will work with jets, ranging from 178 to 220; the preferred setting for maximum performance will be in the 190 to 210 range; this applies to the 125 to 500cc engines. The pilot jet must be at the +50 range with the 50 being the best overall (this is part of the STIC power jet system). The air screw must be in the range of 2 to 4 turns out. New Keihin STIC carburetors from STIC have the new longer (+.100”), stronger piano-steel spring; so, no worry about the air screw working loose. These new springs are available from TOKYO, Harris, and STIC factory. If STIC adjustments are needed; first work with the needle clip position, top clip will make the mixture leaner, the bottom clip will make it richer. Adjust accordingly to your preference. It is my estimation that one must use a needle with the top straight section being at least. +. 106" in diameter; this starts with the JD red II-II, JD Blue IIII, the Yamaha N3EJ at .107.5" and the Suzuki NEDK needle is +. 108."

STIC tuning procedure; be sure to check for clean air filter, check the reed cage for any petal wear. Check the float needle valve for wear; set the float according to specs (there are several great videos). Do not run the vent lines into the air box; this will cause the carburetor to run lean. Do not run the fuel bowl overflow vent tube in any upward position; it must be pointed down; if you run the vent lines upward make sure they are pointed down at their ends.

Before making any major jetting changes; first, experiment with moving the needle up and down; the top clip is leaner; the bottom clip is richer. When you feel you have a good needle position selection and having the air screw at the recommended settings; adjust the front air screw in small increments; not going below 2 turns. A larger air screw setting air corrects the larger pilot jet and allows more air to go into the main jet power inlet. Going to a larger slide will also correct a low-end richness. The standard aftermarket Keihin Shorty comes with a 6.5 slide; JD Jetting has the larger #7 and #8 slides.

Even though others may disagree; the engine should be warm before attempting any STIC jetting decisions. Believe it or not; oil and fuel can and do accumulate in the case and transfers and combustion chamber. When installing the STIC metering system; and before making final jetting selections; here is my advice; install a new spark plug and run STIC for at least 30 minutes at various speeds to help clear the case, cylinder, head combustion area and the engine of any raw fuel left from the previous carburetor.

In summary, do not be lured into using a smaller pilot and main jet; the main and pilot are designed to do certain things in harmony, and they are heavily air corrected. Even though the STIC will run with smaller jets, there is a substantial increase in power by using the larger jets. The STIC is heavily emulsified with air and other forces; using the smaller main jet will tempt you into making corrections in the wrong manner. The STIC has a multiplying (increasing) fuel curve, an instant acceleration and power system. The STIC is an entirely new process and requires learning new things; feel free to contact STIC headquarters for any assistance and upgrades; glad to help and answer any questions. Enjoy.
 
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