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Discussion Starter #1
Anyone on the US based forums most probably will have seen these. It's a replacement part for the keihin carb.

The spec sheet reads like a JML advert. More power, response, better economy, changes for altitude and will do the hoovering!

Ahuh I thought but winter is here and game of thrones ain't on so might as well be in the workshop.

First of all . It's bloody expensive for a block of aluminium. £255 from Tokyo offroad with the supplied needle plus another 71 dumps import duty.

The idea is is to add more air and atomize the fuel better and earlier in the metering block.
Comes with recommended jetting of a 50 pilot, 182 main and a yamashita needle.

Fitting takes all of 10 minutes. I'd familiarised myself with the bike as it was , swapped in the stic and tried it out.

Started first prod but the tickover isn't affected by the air screw as it had been so needed 3 turns in on the tickover screw.

The Base setting is 3 turns out on the airscrew.

First ride wow it's smooth. Don't notice any more bottom but it's amazingly smooth from bottom-mid- top.

Running slightly lean so go with a 186 main jet and it's perfect.

The increase from mid to top is very impressive. What's more impressive is the smoothness. It revs faster too as it's atomizing the fuel better.

It all sounds like snake oil but it really does work. This was all done by butt dyno but the online results I've seen on thumper talk shows 15 percent midrange. 10 percent on top and and it hangs onto its revs longer.
If your bike isn't already dialled in you'll notice an even bigger improvement. Really worth while mod.
 

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You should speak to mog on KTM Thumper Talk albeit he is based in the UK. Has extensively tested the STIC and has had dyno runs done with it.
 

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Discussion Starter #3
Yeah I saw some of his posts and dyno runs. He Has some very impressive gains after a lot of hard work.

There's a wealth of information tuning which was missing when the product was first released and the unit has gone through a few revisions too.
It's a lot easier to set up now for sure
 

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Discussion Starter #7
Lol it sure is.
Is it worth the expense? Most people who buy these are people looking for more power and revs.
It adds more poke than a aftermarket pipe or cylinder head IMHO but £300 would buy you good porting job which would most probably give you more power than the STIC.

However its ace card and the most surprising thing is how much smoother and more tractable it is. All 2 strokes lurch to a certain extent as the jetting circuits overlap. This doesn't. If you use your bike on the road between the trails it's awesome. It allows you to hold a perfectly steady rpm/throttle.

It's faster low down as there's no dips/peaks in the power. You do have to manage the right hand better as it revs faster but after riding it all afternoon I'm sold on it.

Another point I'd done some top speed runs yesterday. 13:50 gearing. Speedo says 91mph. GPS was a true 88mph.

Hour later with the STIC it pulled 92mph GPS. Thats purely down to the extra revs it was making and hanging onto its power.
Not a very scientific experiment but nice to know ?

So is it worth it? I've wasted more money on worse things.....

If you have a keihin already I'd say yeah it's worth it. More power, more revs, smoother , more tractable
 

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All 2 strokes lurch to a certain extent as the jetting circuits overlap. This doesn't. If you use your bike on the road between the trails it's awesome. It allows you to hold a perfectly steady rpm/throttle.
You've started an interesting thread, an alternative to the metering block could be an Lectron and that really only has one metering circuit so there is no overlap of circuits. (It does have a PJ circuit but you certainly don't feel that circuit kicking in or out). The Lectron is no cheaper than the route that you went down and it still needs fiddling with in order to get it spot on!
 

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Discussion Starter #9
I have used a lectron before but never tried one back to back with a keihin.
There's a channel on YouTube called Tokyo offroad . He tries back to back with smart carb, lectron, mikuni and a normal keihin.

It seems to work by using the pilot jet to inject air into the main. This allows more air mixed with the fuel hence more power and better response.

From what research I've done whether your on a 125-500cc . Sea level to 6000ft most of the users of the STIC are within a jet size or 2 away from each other which means it really does compensate for altitude and temps.
 

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You've started an interesting thread, an alternative to the metering block could be an Lectron and that really only has one metering circuit so there is no overlap of circuits. (It does have a PJ circuit but you certainly don't feel that circuit kicking in or out). The Lectron is no cheaper than the route that you went down and it still needs fiddling with in order to get it spot on!
Tokyo preferred the Stic


Sent from my iPhone using Tapatalk Pro
 

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The described effects - better evaporization, better mixture - will definitely affect how the engine runs and responds. So it is very likely that the "main jet tube" does what the producer promises, I dont doubt that. I'd love to try it but of course the price is far too high.

What I think is strange is the fact that STIC says you need to run 98 octane fuel and recommends high pressure gear oil due to the tremendously increasing torque and hp. Come on...are they serious?
 

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Probably just covering their asses steveman. Interesting how they don’t mention the extra load increases may affect the parts outside of the motor! Even suspension and chassis will be getting a harder time with all this “extra power/torque”.

Is there any actual graphics to show this increase? It’d have to be a hell of a lot (like double) to be a concern surely?
 

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The described effects - better evaporization, better mixture - will definitely affect how the engine runs and responds. So it is very likely that the "main jet tube" does what the producer promises, I dont doubt that. I'd love to try it but of course the price is far too high.

What I think is strange is the fact that STIC says you need to run 98 octane fuel and recommends high pressure gear oil due to the tremendously increasing torque and hp. Come on...are they serious?
I've not read the gumph but it annoys me when the wrong terminology is used, I've messed about with 4 barrel carbs on a lot of V8 engines and have learnt a fair bit on the way. In a performance engine the fuel needs to be finely atomized, you do not want it vaporized, the two are not the same thing, the latter is good for MPG, not BHP, the only way that the fuel will vaporize is manifold heat (in our case heat from the crank cases) and low pressure in the cases which causes the fuel to boil, the metering block won't an affect on either of these.

An atomized fuel will contain many small drops of liquid fuel, a vaporized fuel has boiled into a gas, the gas vapour will mix very well with the air so burns well but the vapour occupies much more space which displaces air, this causes the volumetric efficiency (VE) of the engine to fall which is no good for peak BHP. The VE of the engine is low when cruising around because the carb is throttling the engine anyway so at low throttle settings the low VE does not matter.


The metering block and its sub components can determine how well the fuel is atomized and even though the fuel will tend to 're-blob' as it travels down a manifold or in our case around the crankcase it is still worth trying to atomize the fuel as well as possible.


As to the high pressure oil, who are they trying to kid!
 

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Discussion Starter #14
Had a ride out yesterday on it. It's brilliant.

Never been on a carb bike that's so smooth yet powerful. Even though it's making more power it's actually easier to ride as it's so predictable.
At the end of the ride there's a massive hill to climb. Just to test it I rode it 2 gears too high in 4th just lugging it to see if it would pull it. It chugged itself all the way to the top.

The suspension feels better too which is another benefit I wasn't expecting. It's something I never noticed before. When the bike came onto the pipe the tyre breaks loose. All 2 strokes do to a certain extent. I'm assuming because there's less dips in the torque curve the suspension is more settled.

Lectrons are known for being super smooth once set up but get a bad rap for taking the edge off the performance. Imagine smoothness of a lectron, response of a tpi with the bark of a well set up keihin but with even more revs and power at the top.

My friend has a tpi and it says a lot when he commented on its smooth power. It did however put him on his arse instantly when he turned the throttle. He wasn't expecting so much poke straight off the bottom. He said he'd fit a throttle tamer cam to make it perfect for him.

If you check thumper talk there's lots of independent dyno tests and they have all been impressive. Cr250 was recently put on the dyno and it made 12 percent extra at peak power.

The dyno can't pick up the response or the way it fuels though. As impressive as the extra power is its the way it lugs, speed it revs and total smoothness which is more fantastic. I've bought loads of shit for my bike from carbon subframe, ohlins suspension, rekluse, tuned cylinders blah blah but it's the best mod so far.
 

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Discussion Starter #15
The described effects - better evaporization, better mixture - will definitely affect how the engine runs and responds. So it is very likely that the "main jet tube" does what the producer promises, I dont doubt that. I'd love to try it but of course the price is far too high.

What I think is strange is the fact that STIC says you need to run 98 octane fuel and recommends high pressure gear oil due to the tremendously increasing torque and hp. Come on...are they serious?
I personally run 98 so haven't tried it on 95. When the stic first came out 18 months ago the manufacturer claimed you should run it on race fuel lol
I think it's all A) cover themselves b) to make the most of the part. I don't think it would be massively detrimental to performance running 95. Doubt you'd tell the difference.

They also claimed less compression for full effect. I'm near 13:1 compression and 230 psi with negative deck height (lifted cylinder) so wasn't sure how it would respond to this but it's not affected. Who knows. With less compression it might be even better giving it even more revs.
 

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The funny thing is, that the british term "vaporized" isnt even correctly translated to German as the German term which is used is not 100% exactly what is meant in British/English language. Atomized and vaporized are very different in my language while "atomized" isnt even used in highly technical descriptions of modern FI petrol engines.
However, I know what you are talking about. I do believe that the system works and having read sand300's description I can say I dont have the slightest doubt. Unfortunately its too expensive for an unemployed old bastard like me but I guess it would be worth buying. Me too bought a lot of unnecessary bling and stuff but this little piece of alloy would make sense...

And I am not surprised about how the yanks advertise, there is a lot of people there who never scrutinise things. I wouldnt care about peak hp, more torque etc, the main thing is, as described by sand300, that the motor runs very clean and smooth. Something which is hard to gain with twostroke carbs.
 

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April 16, 2019

STIC (Rich off idle) Tuning instructions:

Often the use of an older carburetor may need to have a new float needle for the seat (referred to as the needle and seat). After some age and wear; the float level will typically be higher, and this would cause a rich condition when installing the new STIC metering system. It is important that the float level is checked to make sure it is within specifications to 1/16" lower. A worn needle and seat are typically indicated by a rich condition off idle. The rich condition could be associated with a float that has picked up the additional weight by absorbing fuel.

I would suggest you order several of the float needles and recommend your customers install the new needle for the float to insure proper sealing. I would also ask your customers if they are using the stock jet tube needle and suggest they order a new N3EJ from you to keep in their tuning arsenal. I typically have 40/50 of the N3EJ needles in stock. I have also addressed the issue of the air screw not being opened with enough turns; it must be 3 to 4 turns out. Less than the three turns this cause a rich condition from zero to quarter throttle. Most of the customers are at one/two turns out; this is not enough as it should be 3 to 4 turns out.

The larger air screw setting will siphon break the larger pilot and will correct the rich problem at idle and 1/4 throttle. The larger pilot is part of the STIC power system; this allows the pilot fuel and its related air circuits to be blended into the main jet tube outlet. We know the STIC will operate in a larger spectrum of jets ranging from 170/200. The higher horsepower gains are in the upper range of jetting; with the 125's and 300's like the 195/200 mains. Contrary to previous thinking; the 200 main jet set-ups have been tested by JD jetting (James Dean) at +6000 feet with great success. This is posted on KTM Talk.

In summation, the greatest power gain when utilizing the STIC metering block is in using the larger main jets (190/200) and with the pilot jet in the range of (50/52). The STIC process has heavy air emulsification and vaporization and will easily compensate for the larger fuel source. Typically, the needle tip and STIC jet tube outlet will be the determining factor in how much fuel comes out of the system. The air/fuel/vapor acceleration rate progressively increases the flow speed and volume; this intensifies the vaporization and performance pulling more of the pilot jet fuel and its related air circuits into the main outlet. As I said the float level is critical; needing to be at the standard factory level to 1/16" less (lower). The reason being the STIC metering block moves the air fuel vaporizing level above the wet level (float level); near the top of the tube and above the pilot jet passages as they enter the idle intermediate outlets into the carburetor bore. For tuning assistance 1-715-479-7822 or email at [email protected] — George
 
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