I am the owner of a Honda motorcycle [CBX1000] who lives in Hiroshima City, Japan. I am posting about FCR carburetor and CBX1000 customization. I also post about things other than cars and motorcycles. We will post information that will make bikers around the world happy.
Rather than posting about FCR tuning, my blog posts about tuning the FCR of the CBX1000. There should be some useful content for those who are tuning the FCR of an SR. As it is written by an amateur, it may contain incorrect or misguided content. If you use it as a reference, please do so at your own risk. So I will continue writing. Let's get started!
FCR has a lifespan.
Anything that has moving metal will wear out and be scraped. FCR is a racing part. Its durability is low, or rather, it is not well thought out. However, there are many replacement parts and the parts themselves are easy to obtain. Among them, the FCR body is the part that does not have a replacement part, or the main body needs to be replaced when it is damaged. When the throttle valve moves up and down, the FCR body is scraped. When the FCR body is scraped, a rut is formed in the scraped part and the throttle valve cannot move properly. This is the disadvantage of the FCR. The TMR body cannot be scraped due to its structure. To go off topic a little, the weakness of the FCR is that it is not good at fine-tuning the acceleration pump. It is more than a weakness, it is a disadvantage. As far as I know, in the modern age of 2023, there are three countermeasures. ・Wide roller This is a method of changing the size of the throttle valve roller to straddle the rut of the body. You can see it on Yahoo Auctions.
・SEP bearing guide I have installed it in my CBX1000. This kit prevents the throttle valve roller from touching the FCR body directly. It was developed by a volunteer from the factory management. Thank you very much.
・Keistar, Reverse Resuscitation Kit This is an FCR repair kit sold by a company called Keistar. A stainless steel plate is attached to the body of the FCR to remove ruts on the body. It is both a revival and a preventative product.
I was a little disappointed when I found out that FCRs also have a lifespan, as I thought I had made an expensive purchase.
We normally stock about 100 different types of jet needles, both large and small.
For information on the standard stock of FCR slow jets, please check here. ↓Active's website will open in a new tab↓ http://www.acv.co.jp/products/00789
There are 71 types for small and 64 types for large, totaling about 135 types.
The manual says there are tens of thousands of combinations, but in reality you can only choose from 71 types for small and 64 types for large.
Stock other than the standard stock can be purchased within a month of ordering if you order 20 or more.
The CBX1000 has a small body, so the taper you can choose from [E], [F], and [G]
The cutoff you can choose from [M], [T], and [Z]
But basically, the cutoff of [T] is used.
The appropriate number of clip steps will change when the taper is changed.
[E] → [F] → [G] will shift by 2 steps.
90ETM#2 90FTM#4 90GTM#6 are the appropriate number of clip steps that are roughly equal.
Realistically speaking, the cutoff cannot be chosen except for special orders. If you want to change the number of clip stages, you can change the taper to accommodate this, which can be understood from standard stocks.
Jet needle taper and clip stage
This is about selecting the taper of the jet needle of FCR. My current jet needle is for small body. It is 90FTM. The [F] part is the taper. The [T] part is the cut-up. This is the basic position of the clip stage. The [M] part is the straight diameter. For small body, you can choose from three types of taper: [E], [F], and [G]. When tuning FCR, the influence of the taper is about 3/4 throttle opening. If you want to change the taper, the appropriate clip stage will change by two stages as mentioned above. I had a sad experience. When using 90FTM#2, if you want to change the throttle opening to about 3/4, you have to use 90EZM, but I bought 90ETM and 90ETN. I ended up buying 12 jets that I can't use. If I had known about the clip stage, this wouldn't have happened. In reality, if you want to increase the clip stage with 90FTM#1, you will have to make a custom order except for changing the taper angle. Please be careful not to make unnecessary expenditures.
Keep a spare jet needle clip on hand at all times.
Because the jet needle is easy to access, it is sometimes necessary to change it while out and about. When changing the jet needle clip, it can fly off somewhere with great force. When tuning outside, it is essential to have a spare. FCR's e-clip is a special size of 2.5. Replacement e-clips can be purchased at a hardware store.
FCR Beginner’s Guide – Where to order jet needles?
As a general rule, you should buy from the distributors Active or BITO, rather than from Keihin, the manufacturer of FCR. You can also purchase from various e-commerce websites, but the distributors have the largest stock. BITO has the largest stock. I was also able to call them directly to inquire about stock availability.
The surprising moment when I tried tuning my own FCR – for beginners – Failures 2/3【summary】
The reason I'm writing more about what I did wrong than what went wrong is because people often learn from their mistakes. Please read about the mistakes first so that you don't make the same mistakes. See you again!
