FCR Tuning – Trial run of pilot screw Slightly rich

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FCR Tuning – Trial run of pilot screw Slightly rich

I did a test run of FCR tuning and took pictures of the rear area.
If anything, the story is mainly about the test run.
It's around 13 when idling, and I cut it down to about 12 with partial throttle opening.

current tuning

[Current tuning]
AS-1.55 minutes return
PS-3.15 minutes return

Acceleration pump diaphragm KLX250
Acceleration pump discharge large ring 2.3mm
AS Uotani SP2-Ignition [1]

The screws are not misaligned in each cylinder and are synchronized. My CBX is doing very well.

Every time I tune, I think about various things.
The theme this time is
① Do not let the throttle valve hit directly when the accelerator pump discharges.
②When idling, the air-fuel ratio should be around 13 when the throttle is fully closed.
It's mostly about ②.
I'm thinking based on when the engine is warmed up.

My impression is that it has a very mild feel and is easy to ride.
Engine startability is also better with an air-fuel ratio of around 13 when fully closed.
If you aim too hard at cold engine startability, you will end up with an air-fuel ratio of around 11.0 when the engine warms up.
You can't know things like this without an air-fuel ratio meter.
Because there is an air-fuel ratio meter, it's easy to get caught up in the strange things.
I have heard from other tuners about this area, and it seems that each person has their own particular preferences.
Some people set the air-fuel ratio to around 15 when idling and only let it idle.
I tried making it look similar, but it didn't really suit me at the moment, so
The air-fuel ratio is around 13 whether the throttle is fully closed or the throttle is slightly opened.
While driving, I adjust the screws by touching the screws and adjusting the PS as much as I set the AS back. The AS Uotani SP2 settings are also listed, but as far as the ignition curve is concerned at low openings or low rotation speeds, I believe that there is no need to take it into consideration.
Low throttle opening is an item that has a considerable effect on the driving feeling when driving around town.
It also depends on how you ride and whether you open the throttle early or late.
As long as the engine starts, the motorcycle can run.
Although it is listed as rich, it is around 11.5 on the air fuel ratio meter.
A level that causes black smoke to come out of the muffler indicates too much fuel.
You will have to start over from the beginning.

For FCR beginners – How much should I check about the condition of the car body?

Engine compression, plug sparkle, carb blockage, etc.
I can't talk about tuning unless they are in perfect condition.
That's what a tuning professional once told me.
However, unless everything is new, it will not be possible to tune it.
I tune with the assumption that items that have not been inspected are working 100% correctly.
I'm sorry that the work was delayed while I was checking that everything was perfect.
If the motorcycle can be driven without any trouble, we will begin tuning.
I try to check it when things are bad.
If you are tuning the FCR and find that the plug is not working well or there is no fire,
There is a high possibility that you forgot to attach the plug cord or that it is missing from the root.
There have been cases where the problem was caused by attaching and detaching the carburetor or tank.
If fuel is not flowing, it may be the fuel filter.
The PS may be too tight or the fuel may be running out.
If your engine has low compression or is blowing excessive white smoke, please consult your custom shop.

rear view photo

I am shooting from the bottom to the top. It's commonly known as Aori.
The motorcycle looks larger when photographed from below at an angle.
If you take a picture of a motorcycle using the zoom lens, it tends to look smaller.

FCR Tuning – Trial run of pilot screw Slightly rich【summary】

I didn't know if PS was working.
It happened to be in a condition where it could run without any problems, and I was able to return the pilot screw properly.
Currently, I am fixing the JN jet needle and trying not to change it.
The tuning manual says to start tuning by setting the PS back to 1.00.
There is a way to tune the PS by setting it back to 1.00 and basically not touching it.
In that case, you will have to exchange JN and SJ to make up the balance.
If you cannot select the JN count, you will have no choice but to adjust the balance with the screw, so the range of screw return will be somewhat strange.
The current number of clip stages is 90FXT#2, which is one step leaner than BITO's default 90FXT#3.
I think it would be a good idea to experiment with the number of clip stages because the ride quality changes considerably depending on the number of clip stages.
Thank you for reading to the end even though you are busy tuning your FCR.
Please be careful of accidents and troubles and enjoy your FCR tuning life.
Well then, see you again!
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