CBX FCR tuning jet needle replacement. Impressions from a test run after changing the taper angle

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CBX FCR tuning jet needle replacement. Impressions from a test run after changing the taper angle

When I started tuning up FCR, I got stuck in this swamp, so
There are two items I was trying not to touch.
Tapered angle and cut up.
I was thinking that it would be nice to be able to touch it lightly and check whether it's doing well or not.
As I continued to touch it, I became more and more concerned about it and couldn't help it, so I decided to try changing the taper angle.
The reason for changing the taper angle is that when the throttle opening is 1/2 and suddenly opened
There was a phenomenon where I had to wait to open the product, but I feel like the symptoms change when I reduce MJ. There seems to be no change in symptoms even if the SJ is changed. Changing the straight diameter of JN does not seem to change the symptoms.
In such a situation, there was an item that I had not tried: changing the taper angle of JN.
So, the JN jet needle I purchased
There are 12 pieces in 2 types. When you start stocking different jet needles such as taper angles and cut edges,
I was hesitant about what to do because it would be quite a hassle in terms of both the amount and the number of books.
With SR, the lineup is large enough that you won't have any problems with most JNs.
I am complaining about the increase in the number of JNs, but the reason why I bought two types is
I try to do an AB test when tuning up.
Did it get better if you didn't test by changing the values for the same item? Has it gotten worse? Because it cannot be determined.
The taper angle is an item that I have never touched, so just changing the taper angle will only tell you the difference depending on the taper angle. By changing the taper angle and replacing the straight diameter, you can determine whether there is room to tighten the tunings. It’s important to understand numbers and logic, but don’t get too big-headed.
In any case, it is important to exchange them and find the feeling that you like.
I'm in a situation where I keep changing JN over and over again because I don't like it.

Impressions of the test run and negative results.

Based on the results, the thing I don't like is most likely the number of clip stages!
After changing the taper angle, the cold starting performance was not bad and was rather promising.
Adjust the screw, adjust the number of clip stages, change the straight diameter,
When I was trying various things, I gradually changed the number of clips from 2 to 5.
It doesn't rev up around 1/2 throttle opening. It feels like it's waiting to be opened.
It's the throttle opening, but it doesn't feel like it's going to increase any further.
When I thought about it, I had always tried to limit the number of clip stages to 2 to give myself plenty of time.
This is the first time I tried swinging it in an extremely rich direction.
tunings by changing the taper angle will be discontinued for the time being.
And then I will buy a new JN.
It's 90FZQ.
This is a round-up change. JN used when the number of clip stages exceeds the adjustment range.
I had originally heard about BITO's tunings, so I thought I should try JN with a different rounding.
I didn't hesitate. If I hadn't heard about the initial shipping tunings from BITO,
You may have been thinking about it for a while.
In this respect, I realized that comparisons with other motorcycles are important.

For FCR beginners – Throttle wire

I try to remember as much as possible how I felt when I was a beginner as I write this.
I try to write about places that can be set up without tools, jets, or knowledge.
Regarding the throttle wire, the play should be as small as possible, and the return should be moderately strong.
You should. The reason is because it's a racing cab.
Play is essential, but it should be kept as small as possible.
If there is no play, the throttle will open even with the slightest touch or the movement of the motorcycle.
There are advantages and disadvantages regarding return, but there is nothing bad about retuning quickly.
As for the shortcomings, the quick return means the throttle tends to be heavy.
You will need to adjust this area to your own preference.
When installing or removing the carb, check the throttle wire as it is not a part that takes time to adjust.
Please make sure to do this. By the way, the old model of CBX FCR has two throttle wires,
It is essential to check that the throttle valves are fully open on all cylinders when fully open.
In rare cases, the throttle wire may be installed before the throttle is fully opened.
Please note.

CBX FCR tuning jet needle replacement. Impressions from a test run after changing the taper angle【summary】

If you change only the taper angle with JN count and keep the number of clip stages the same, the result will be in an unexpected direction.
It seems that the rich and lean tuning may shift. If you actually measure JN with different taper angles, you will definitely notice a difference.
It may be better to realize that if the taper angle count is different, the straight diameter is the same, but it is a different JN.
[E] and [F] are the differences in taper angle, but since the notation is written first, I am interpreting it as if there is a meaning as a priority order of the differences.
Roughly speaking, I think the difference is about 3 clip stages.
The number of clip stages should be about the same for 90ETM#3 and 90FTM#6. Please consider it as a reference for lean and rich.
There are blog articles and videos on the internet that show actual measurements, so please check those sites for more information.
I will measure it accurately and post the numbers for my own knowledge.
Regarding JN's taper, it is not a good idea to just change that part, but it is better to change the combined part to a greater or lesser extent.
Affects the whole world.
You may be prepared to change to a different jet needle and redo the tunings.
I'm in a state where I'm groping for things I don't have a clear answer to, so this is a fluffy story.
However, I tried tuning the FCR little by little without stopping,
We will keep various records.
I hope you all have a fun FCR life.
See you again.

Reference photo

I will post photos and work photos that may be helpful for tuning up the FCR.
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