FCR tuning – Adjust throttle return. Turn the pilot screw.

CBX FCR
CBXFCRMaintenance
This article can be read in about 8 minutes.

FCR tuning – Adjust throttle return. Turn the pilot screw.

Added on 2024/02/14.
I wrote this post when I couldn't use a cab driver. In reality, the changes in PS are noticeable.

It went from idling to 1/8 all at once, so I touched the PS pilot screw and AS air screw.
I've been thinking about this for a long time, but it's hard to tell if the PS pilot screw is working or not.
I don't know if there is a change when I touch the PS pilot screw, so it may be a placebo effect.
I try to touch it just in case.
*By the way, regarding the notation of the screw, the minute is written as a clock hand.
It is divided into 60 parts.
PS 1 and AS 35 minutes
PS 1.30 minutes and AS 45 minutes
If you compare it with the amount recorded in the video, I feel that the return is slightly better.
I feel like I took a test run,
Idling → 1/16 → 1/8 → 1/4
There is no extreme rich or lean between them.
Apparently it doesn't seem to lack a sense of power.
It may not make sense, but I'm thinking of changing the SJ to 48 or 50 and opening the AS air screw a little more.
Is the meter the cause of the return to idling? Is it because of the tuning? Is it due to fcr deterioration? It's unclear. When I was doing tuning work, there were times when the return was extremely slow, so I'm going to try adjusting the tunings again based on the premise of tuning.

CBX FCR response return – with images and videos

FCR

PS Pilot Screw Adjustment – Cab Driver

I use a carb driver for PS pilot screw adjustment.
The cab driver may separate from the screw during adjustment.
This is caused by the fact that the carb driver is not properly engaged with the PS pilot screw.
Since it often separates during the process, I often end up having to remove and install the carb to check the return rotation speed of the PS pilot screw. In short, it is in an unfortunate state that it cannot be used properly.
Then I stopped the engine and turned the PS pilot screw. I would like to be able to run the engine as much as possible without stopping it, but it is currently difficult to do so.
[Current tunings]
PS-1:30 minutes
AS-0:45 minutes
JN-90FTR#3
SJ-45
MJ-122

FCR tuning – Adjust throttle return. Turn the pilot screw.【summary】

As I wrote at the beginning, I am not yet able to experience the effects of the PS Pilot Screw. It may be a placebo effect that there is a change when you touch the PS pilot screw.
Also, my CBX may be having trouble with the PS pilot screw.
Either way, the basics are to return to 1.0 and proceed with the tunings.
If the SJ slow jet is made larger, the AS air screw can also be opened wider.
Since it is possible, next time I would like to change the SJ from 45 to 48 or 50 and check the low opening tuning.
At the moment, I think that the reason why the engine stops for a moment when the throttle is returned is because the air-fuel ratio is extremely different depending on the throttle opening from idling to 1/16 to 1/8.
I hope I can find an answer that satisfies me, but if I can't, I'll try not to think about it too much since I'm still running.
The FCR tunings are not paper-based, but are uploaded to the cloud along with the date.
I save it on my smartphone so that I can quickly check the contents. In my case I'm using spreads on google cloud.

Regarding the PS pilot screw, simply opening and closing it will affect the air-fuel ratio from idling with the throttle fully closed to slightly opening the throttle.
As a characteristic of the CBX, it was stated that it was unclear whether the PS pilot screw was effective or not, but it is quite effective. However, there are cases where the PS pilot screw does not work.
The cab driver is compatible with CBX.
Now you can clearly see the air-fuel ratio while the engine is running.
The PS pilot screw will not work if the SJ is too large or the idling stop screw is set too high. It can be idle even when fully closed. I think it has something to do with the idle port and slow port.
It would be nice if I could verify the return using a new carburetor and a new meter.
It seems unlikely that amateur DIY will be able to achieve that quickly.
There is a possibility that I will buy FCR again, so I would like to compare the old and new one.
Well then! See you again!
Copied title and URL