FCR Tuning – The number of clip stages of the jet needle is determined by the driving feeling

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FCR Tuning – The number of clip stages of the jet needle is determined by the driving feeling

Today, I had some free time in the evening, so I went for a test run in the back mountains.
I tried changing the number of clip stages on the jet needle, but I couldn't because it was getting dark.
If you touch the jet needle clip, you will have to redo the air screw as well.
In this blog, I will explain how to choose the number of clip stages for a jet needle.
FCR is interesting no matter where you touch it once you start to understand the logic.
In particular, the jet needle is the most commonly used area on the street.
It feels like choosing the driving feeling rather than tuning.
The number of clip stages is 1 to 7 counting from the top.
If you use a proper jet needle, you can only use it about half of the time.
The half that can't be used is in poor condition to the point where it can no longer be driven.
You can use up to 3 clips above and below the appropriate number of clips.
Even if you change the clip, if the throttle opening is low from there, the throttle opening will be 1/2 or less.
Fine adjustment of the air screw is required.
Even if you don't touch the air screw, the condition will not deteriorate significantly.
If you just want to check the driving feeling briefly, it is a good idea to change the clip and check it on a trial basis.

Confirm the jet needle clip change based on the driving feeling.

You can enjoy changes in the driving feeling that cannot be seen only with lean or rich FCR influence range.
When you have an air-fuel ratio meter, you tend to look at the numbers and judge whether it's lean or rich.
Considering the characteristics of engine revving, etc., there are some areas that are difficult to show in the numerical values.
Simply put, we will change the number of clip stages in order.
Please choose the number of clip stages that gives you the driving feeling you like.
The straight diameter, slow jet, and main jet also affect each other.
If you can drive to a certain extent, try changing the number of clip stages and check the change in the driving feeling on the street, then refine your results.
If you make the clip too rich, you won't be able to run properly.
On the other hand, if you set it to extreme lean, it won't affect your driving, but it will give you a feeling of no power at all.
There are cases where there is a sense of power but the blow-up is not so good, and there are cases where the blow-off is good but there is no sense of power. Please choose the feeling that is just right for you.
In my case, I often set the number of clip stages to 2.
Looking at the value on the air-fuel ratio meter, it seems that there is no problem with [2].
Currently it is set to [3].
I feel that the sense of power and momentum is very good.
It may also be due to seasonal factors or how people feel that day.
I don't know if I changed the related jets or if my preferences changed.
The previous best number of clip stages may not actually be the best.
I choose the number of clip stages based on my preference, not that it's good or bad.

*Note – How to find the appropriate number of clip stages

I don't know how to find the appropriate number of clip stages.
However, I can write about how I found the appropriate number of clip stages.
If the number of clip stages is rich, the engine will not rev up and it will be difficult to drive, so you can immediately tell whether it is appropriate or not.
When it comes to lean, it feels like the power is gone, so it's hard to understand.
The most difficult thing to understand is when the number of clip stages is already [1] or [7].
I can understand either rich or lean, but there are not enough columns, so
You cannot try to change the other one.
The usual method is to try changing the sharpness of the jet needle.
It is not possible to specify a fine count when it comes to rounding up, so basically it is the rounding up of [T].
Please check below.

Active Japan's site will open in a new tab.
The tuning manual says there are 10,000 types to choose from.
There are actually 100 types. Among them, the jet needle that can be used for your own motorcycle is
It has been decided to some extent. You have fewer choices.
In the case of CBX1000, if it is [E] taper, the number of clip stages will be out of the appropriate range unless the straight diameter is extremely thick.

My CBX1000 FCR is in shipping condition.
The standard for the range of influence in the tuning manual is also [F] taper.
Since there is only [T] for cutting, in order to change the number of clip stages,
I have no choice but to change the taper.


The effect appears to be that the rounding is changed.
Strictly speaking, the taper angle is different, so the feel will be different, but
Currently, if the number of clip stages is insufficient, the only option is to replace the taper angle.
By the way, the current FCR jet needle for CBX1000 uses 90FTX.
In the case of I
I think 90FXM#2 or 90FXM#3 is appropriate.
This does not mean that the number of clip stages is correct.
Once you find the number of clip stages you like, it is fun to choose the slow jet and main jet from there.

For FCR beginners – be aware of and anticipate what has changed

You can predict where and what kind of influence will be affected when tuning, not just the jet needle.
Doing some research will be very helpful.
for example…
[Example 1] When replacing the main jet, the tuning manual states that it does not affect throttle opening 1/2, but in reality it may affect engine speed around 3/8. Masu.
[Example 2]
The pilot screw changes the startability of the engine and the feeling at low openings around 1/16. This item is difficult to understand unless you are conscious of whether or not the pilot screw is making a change.
There are two types of low throttle opening: idle port and slow port.
The idle port is effective even when the throttle is fully closed. The slow port is affected next to the idle port when you start opening the throttle. If the idle port is appropriate and the slow port becomes significantly lean, if you are not aware of it, it will continue to be in a strange state and the cause will continue to be unknown.
If you are conscious or know in advance that you have such symptoms, you can take countermeasures such as changing the slow jet to a rich one since the slow port is lean.

In general, there are some changes that are not specifically described in the tuning manual, so
What changes when you touch it? This symptom is most likely caused by the pilot screw.
You can gain a lot by doing your homework and having information beforehand when tuning.

FCR Tuning – The number of clip stages of the jet needle is determined by the driving feeling【summary】

This is my own way of thinking about the number of clip stages of a jet needle, so I apologize if I write something that is off-topic.
In addition, the combination of straight diameter and slow jet improves engine startability,
There were times when I felt that the driving feeling at low throttle openings had improved dramatically.
I also tried main jets from 102 to 138.
With 100 lean main jets, I could not feel any change.
Around No. 125, the feeling around 1/2 throttle opening changes, and the changes are fun.
Even if you just change the first gear, you can get a sense of it, and if you change it to second rich, you can feel that the acceleration has increased.
If you try to tune on public roads, the tuning will be centered around low throttle openings.
On mountain passes, etc., I use the throttle opening at around 1/2, and in a straight line, I open it to about 3/4.
This is an item that allows you to enjoy tuning by selecting based on feel without relying on an air-fuel ratio meter.
Feel free to change the number of clip stages on the jet needle whenever you feel like it.
You're sure to discover more interesting things than you imagine.
I hope you all have a fun FCR life.
See you again!

*CBX1000 photo gallery is posted at the bottom.

CBX1000 photo gallery

This is a photo taken during a test run around 5pm on the evening of 2022/11/04.
Lately, I've been checking the FCR to see if the engine speed is dropping.
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