FCR tuning – MJ or JN – 2022-06-20

FCR tuning – MJ or JN – 2022-06-20

I couldn't help but worry about it, so I decided to leave work early in the morning and finish by noon to set up. I don't like worrying about it until the rainy season starts.
In addition to the four seasons, Japan also has seasons during spring and summer when it rains a lot.
As for the current tunings, we have advanced the ignition timing, so we are making changes accordingly.
I'm not satisfied, but I feel like it's not bad.
This time, MJ was changed and JN was changed accordingly.
What happens if you change it? I want to know.
What I want to do is follow MJ
MJ-132
→
MJ-138
to change to.
Is the current MJ good? Is it bad? I wanted to see if there were any other changes.

work photos

Photos that appear to be before and after removal of the tank.
Since I have removed the carburetor many times, I am concerned about synchronization.
Recently, people have learned to adjust the amount of gasoline in advance when installing or removing the tank.
Since I am doing it outside, there is always a test run involved, so a skill I recently learned is to avoid putting stress on my lower back.

tuning change. Focusing on MJ changes.

Current tunings
AS-1.35 minutes return
PS-1.15 minutes return
SJ-55
JN-90FTR#2
MJ-132
→
PS-1.00 minutes return
MJ-138
@It feels easier to ride when the throttle opening is less than 1/2. When the throttle opening is 1/2 or more, it's not good enough, so I change the clip and check the range and whether it's rich or lean. I wanted to return PS to 1.00 minutes, so I set it back.
→
JN-90FTR#3
@The unsatisfactory feeling around 1/2 throttle opening got worse. It means it was rich. Redirect the clip in the opposite direction.
→
JN-90FTR#1
@The feeling of bumping around 1/2 throttle opening has been improved. I would like to make another improvement.
→
AS-1.20 minutes return
JN-90FTS#2
@The symptoms improved when the throttle opening was 1/2. On the other hand, it feels hard or rather heavy at around 1/8 throttle opening.
Consider adjusting the screw or increasing the SJ.

If you change one place, you end up not liking that one place, and the jet number is also moving in a strange direction. It feels like it is far from a reference for the tunings of FCR with a similar displacement.
I will consider the next tuning assuming that MJ is too large.

next time
First
Try adjusting the low throttle opening with the screw, and if you like it, finish.
If you don't like it, change the jets to the ones below and try again.
AS-1.20 minutes
PS-1.00 minutes
SJ-55
JN-90FTR#1
MJ-135
I'll try it. As for what I don't like about the bottom, I can handle it by touching the screws, so let's touch on it here and there.

FCR-For Beginners-Throttle opening and rotation speed

When tuning the FCR, which is the standard for engine speed or throttle opening?
The throttle opening is overwhelming. The reason is that everything in the manual is written based on the throttle opening.
Engine speed and feel are the results.
Idling is when the rotational speed is specified. Except for the numbers clearly stating that it is around 1300 rpm,
There are no specific specifications.
There are vague specifications regarding speed, such as low speed, medium speed, high speed, and full load.
There are no specific specifications.
For FCR, engine speed should be considered as a factor when determining results. The manual does not describe how to select a jet for each rotation speed. The feeling is to look at the partial air-fuel ratio for each throttle opening, and the change in feeling when opening the throttle from situation A to situation B, and the speed, number of revolutions, and gears are nothing more than the situation. Ignore the unusual situation of starting in 5th gear.
The throttle opening is also listed on the X-axis of the graph.
There may be people who are conscious of the rotation speed because it says IDLE.
An example of a correct way to express it is to express it as a 1/4 opening partial instead of a 3000 rpm partial.

FCR tuning – MJ or JN – 2022-06-20 【Summary】

When tuning up the FCR, I try to make as many breaks as possible before heading home.
This is because I want to use the time to research, read manuals, and think about what to do next.
I ended up finishing the work with the previous tunings clearly deciding what to do next.
It was just a work in progress.
As a result, I couldn't help but worry about it, so I immediately touched it again.
Because of changes in climate and humidity, it would be best to finish it in one go if possible.
There are times when it's impossible to allocate time due to the amount of work, so I want to be careful about the boundaries between tasks.
I've already decided what I'll do next time, but is there a better way? From there, I would like to think carefully about how to derive it and replace the jet.
See you again!