[FCR] Jet needles should be purchased from BITO.

[FCR] Jet needles should be purchased from BITO.

JN Jet Needle has arrived from BITO.
This is a post about purchasing FCR jets in Japan.
I usually set the FCR with [F] taper,
I have a symptom where it gets richer when I suddenly open the throttle to 1/2, so
As a countermeasure, I tried various things such as changing the MJ main jet to a smaller size, but I didn't get much of a feeling.
It's not good, so I'll change the taper angle to [E] and try tuning it.
Looking at the manual, it seems that the taper angle affects the throttle opening from 1/2 to full throttle and has a balance with MJ.
Ideally, I would like to use a large MJ such as 135. One of the current countermeasures is to reduce the number of MJ in response to the deep bumps caused by rapid opening at 1/2 throttle opening, so I would like to solve that problem. In any case, changing the taper angle is a tuning that I have not tried yet, so
I'm really looking forward to it even before tuning it up.
As I wrote in a previous blog post, I'm a bit picky when it comes to purchasing FCR jet needles, so I'll write about that again. Also, although I have not tried it specifically,
I will also write a little about changes in the number of clip stages.

Recommendation for purchasing jet needles at BITO

*The following information is based on what I researched.
We recommend purchasing a set of MJ main jets and SJ slow jets. Also, even if you don't buy a set, no matter where or how you buy, you won't have to worry about inventory shortages or restocks.
Jet needles claim to have over 10,000 combinations,
To be realistic, the lineup that you can usually get is:
3 types of taper angles, 2 types of cut edges, 26 types of straight diameters
There are 156 pieces, and even if you include special counts for each motorcycle, there are less than 200 types.
Taper angle is [E] [F] [G], rounding is [T] [Z],
The straight diameter is [A-Z], and the inventory rate is high, mainly around M.
That's my understanding. It seems that custom-made products are basically made in units of 20 pieces or more.
Even if you ask about inventory at a parts retailer, the clerk at the counter doesn't know the details, and the person placing the order doesn't know the product lineup either. Also, even if you order online, there are many cases where after you pay, the manufacturer will tell you that the item is out of stock. It looks like the wholesaler is active, but active also has stock issues.
It seems that there are many deficiencies.
Therefore, the best way to order JN jet needles is to call BITO directly.
Is the correct answer. Even if you ask them about the number of items in stock over the phone, they will respond within seconds.
The problem with ordering from BITO is that you can't find out what's in stock unless you call, email, or fax.
Payment will be made by bank transfer or cash on delivery, so you will not be able to receive point refunds, which are popular these days.
At least it's better than ordering online and not getting your money back because it's out of stock.
If you have a close relationship with a motorcycle shop, you may be able to place an order with BITO from there.

For beginners in FCR – before buying jets

Assuming you have the manual and tools, the first thing to try is changing the number of clip stages on the jet needle. The driving feeling changes visibly.
It is necessary to know the current initial values for AS and PS.
For CBX1000, I use the same screw for all 6 cylinders, but depending on the custom shop,
In some cases, each cylinder is set differently.
If each cylinder is set separately, you should be able to adjust it while checking how the idling increases.
It takes courage to touch something for the first time. In the case of CBX1000, I increase the AS in 5 minute increments from the 1st to the 6th cylinder, and when the rotation speed increases, at that point I return the AS to the same value for all 6 cylinders. After that, do a test run and adjust the AS to the best possible throttle opening by 1/2.
Regarding PS, check starting performance when cold and clutch engagement when starting. My CBX1000 is equipped with an air/fuel ratio meter. When I feel that I have a good start, the value often falls between 11.9 and 12.5. When in doubt about PS, I go back 0.45 minutes and then go back 15 minutes at a time to find the best position.
Sometimes you can see a good or bad change after about 5 minutes, but sometimes you can't see any change even if you go back 15 minutes.
We judge it based on how well it starts when cold and how well it starts when the clutch meets.
If the engine is warm, there is no problem even if it is made too thick, but I feel that the starting performance is poor when the engine is cold. I am currently searching for my own theory as it is related to AS.
This is a little off-topic, but before you buy a jet, it's better to touch the parts you touch, even if it's only lightly.
This is the story. Each tuner has different things to say, order of tunings, and preferences.
If you get confused about the screws, just look at the manual and start over.
If you want to get a feel for it, we recommend starting by touching the number of clip stages.

[FCR] Jet needles should be purchased from BITO.【summary】

There are many riders who want to try tuning up a racing caburetor, and who still enjoy it. There may be many riders who ask a custom shop to set it up.
My blog is aimed at people who set up their own devices.
Three types of racing caburetors are currently mainstream: [FCR], [TMR], and [CRS], and in most cases Yoshimura's own multiple jet nozzle (MJN) is also incorporated.
Even though [FCR] has the highest market share among them, it is somewhat sad that jet needles are not available in the market. Owners with [TMR] and [CRS] are having a hard time procuring jets. Yoshimura MJN is a kit that changes the jet needle to Yoshimura's original specifications. TMRs with the Yoshimura logo are sold with Yoshimura MJN installed. Simply put, it is a jet needle that Yoshimura sells independently. It costs about 6,000 yen per bottle, so I'd like to try it too, but I can't afford it.
With 6000x6=36000, you need 2 sets of good and bad, and if you add more from there, you will need at least 1 set, so if you try to introduce it to CBX1000, it will cost nearly 100,000 yen.
According to what I heard from a professional, it won't give you a perfect tuning, but it will give you a great feeling that is close to perfect.
I get the impression that it is a wonderful jet needle.
There is no perfect tuning, so if you want a great feeling, if you have the right tunings,
I would definitely like to introduce it.
We ended up talking about the jet needle, but I will incorporate it into the CBX1000 and take a test run from tomorrow onwards. I'm looking forward to seeing how different the [E] and [F] tapers are.
Also, the driving feeling when using a larger MJ than the rich symptoms when the throttle opening is about 1/2
It's a priority, so if it doesn't improve much, I'd like to deal with it with another approach or riding style.
I hope you all have a fun FCR life.
See you again!