FCR tunings-all changes-22/07/09

HONDA CBX FCR
CBXFCR
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FCR tunings-all changes-22/07/09

The theory of FCR tunings is AB testing, one step forward, two steps back! is.
After about a month of trying various things, I decided to completely change the tunings.
Rather than ignoring the theory, it's the first step in tuning it up.
I've tried a lot of things and have a good history, so I changed everything in one go and started over.
The timing of the screw, synchronization, and accelerator pump is also sloppy, so
Measure carefully before starting.
After the test run, all I have to do is adjust the screws, change the MJ's number 1, and adjust the number of clip stages on the JN.

Pretuning

The tunings have been changed to the point where it can be called pretuning.
I will describe the tunings I made this time.
PS-1.15 minutes
AS-2.00 minutes
SJ-52
JN-90FTS#3
MJ-122
Acceleration pump-KLX250
Discharge timing 2.6mm
Uotani dial advance angle [1]
Water rev limit [6]
It becomes.
I want to open AS as much as possible for low opening.
I'm ignoring the air/fuel ratio meter. Driving feeling when SJ is richened and AS is set back greatly
was very good, so I would like to hire him.
Regarding MJ, around 135 was good, but around 1/2 throttle opening
I chose 122 because the combination with JN was bad and I had to wait for it to open and get beaten up.
This will probably make it richer, so if I don't like it, I'm thinking of lowering the count to a leaner one. Regarding full throttle, the 125 is faster to reach 200km/h than the 115, so I would like to use as large a number as possible.

Gasoline amount in chamber

When replacing SJ or MJ, the gasoline in the FCR float chamber must be drained.
I'm sure there are quite a few riders who don't touch them often and throw them away.
This is the case with CBX. It had 6 cylinders and was full enough to fill one lightweight cup. Fuel hose gasoline,
It's hard to say because each person's oil level is different, but it's quite a lot.
A full lightweight cup is simply 200cc, which is approximately 33cc.
If I want to drain the gasoline without completely removing and installing the carburetor, I give up on No. 3 and 4 of the 6 cylinders and let a rag suck it up.
is. By the way, I have 33cc x 2 and 66cc. Do you think it's more or less?
It's a personal opinion. I use subtanks and reuse them as much as possible.
If you are concerned about dirt getting mixed in, it is best not to reuse it.

For FCR Beginners-6 Vacuum Gauge

For beginners, synchronization is a high hurdle.
And I'm sure there are many riders who want to try synchronization for themselves at least once. I am using a 4-gauge vacuum gauge with a slight modification to 6 gauges.
I will briefly explain this area for beginners.
There's no harm in reading it.
There are two important points.
① Be sure to perform needle calibration.
② Replacement is a waste of time.
Be sure to calibrate the needle before starting work. It has shifted since I bought it new.
Even if you buy something that is expensive, it will still be off. I bought a Daytona vacuum gauge,
The maximum deviation was about 250kpa from the beginning.
If you are planning to synchronize with vacuum gauge on CBX, if you have time to replace 4 units,
It is better to work with 6 sets. I will go deep into the mountains and synchronize under the blue sky, so
Since there is no electric fan, it is better to use a 6-unit vacuum gauge to complete the process quickly.
It would be better to use the time to replace the cylinder for other tasks, and adjusting one location will change the negative pressure in other cylinders, so the work speed will be faster than just replacing the cylinder.

Please refer to the previous article for how to calibrate the needle.

↓Past articles will open. With video↓
FCR synchronization and 6-series vacuum gauge

FCR tunings-all changes-22/07/09【summary】

This tuning was done by removing and installing the carburetor.
Basically, keep a history of synchronization, AS, PS, etc., and how many times have you used it since the last time?
It is based on this idea. If you don't regularly attach and detach the carburetor and match it perfectly with each cylinder,
It is also possible that the screws in No. 1 and No. 5 of the 6 cylinders are out of alignment.
When I replace the SJ slow jet, I reset the screws once and check that each cylinder has the same return. In particular, the synchronization screws and nuts are not the type of adjustment that leaves a history, so
I try to make the height of the synchronization nut the same for each cylinder before readjusting.
Next time will be a test run, but the tunings shouldn't be that extreme, so
I hope that the results will be satisfactory.
I wish I could just compare the number of clip stages between the AS and PS screws and the JN...
I want to have fun tuning it up.
I hope you all have a fun FCR life.
See you again!

*A gallery of work photos has been added at the bottom.

work photos

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