FCR tuning – MJ main jet change 22/06/23

This article can be read in about 8 minutes.

FCR tuning – MJ main jet change 22/06/23

Recently, the situation has become such that instead of tuning up FCR when I have time, I make time to set up FCR. Should I calm my mind down a bit or do it until it doesn't bother me anymore?
I have to do one or the other. Although it is called changing the main jet,
Changed MJ and JN. I had set my sights on it in the previous tuning, so
This time, after replacing it, I will check the AS adjustment and the effectiveness of the acceleration pump again.
I didn't have time so I couldn't do a test run. Today I finished replacing the synchronizer and jet.
This is my impression.
It's close to the ideal rise, but there seems to be room for it to get a little better.
This is the throttle opening that can be resolved by touching AS.
Next time, I will test drive the AS a few times while touching it little by little.


Current tunings
AS-1.30 minutes
PS-1.15 minutes
Acceleration pump - standard
Uotani ignition timing [1]
@1/2 seems a little strange, so I checked until it was rich.

AS-1.30 minutes
PS-1.15 minutes
Acceleration pump - standard
Uotani ignition timing [1]
@It has improved considerably, but I need to do some more test runs and refine it.

Finished with the above tunings.
Next time, we will focus on tuning the AS and accelerator pump diaphragm.

work photos

Maybe my mindset has changed recently, but I haven't seen any pictures of blue skies and motorcycles. On sunny days, I try to include the sky in my photos as well. For FCR, when I touch the chamber area, such as replacing the main jet, I remove the carb. In the photo, the tank is removed, but if you are just touching the MJ main jet, leave the tank attached.
This time, the JN jet needle was also changed, so the tank was removed. On the other hand, if you only touch the JN jet needle, just lower the tank and do not remove the carb.

FCR-For Beginners-Test run and load

When I was surfing the web and looking at articles about tuning up FCR,
You must have seen articles that talk about each gear, rotation speed, etc.
When I set the idling while looking at the air-fuel ratio meter and tried to start,
There are times when you feel empty and have no sense of power.
This is subtly written in the manual, but if a force is applied to the rear wheel,
When it comes to idling and starting, there are some cases where you have to take a deep look.
The manual says full load.
This is because the force with which the engine turns the rear wheels differs depending on the gear and rotation speed.
Even if your car looks fine when idling or racing, something may be wrong when you actually drive it. This is because it does not take into account that the load is on the rear wheel of the motorcycle.
It needs to be thicker because it requires more force to handle the load.
By the way, a low speed gear produces a lot of power with less force. At high rotation speeds, a large amount of power is produced with a small amount of force.
The load differs depending on the speed range when riding a motorcycle.
If you see the words "gear" or "rotation speed" when browsing FCR tuning articles,
It may be easier to read if you are aware of the word load.

FCR tuning – MJ main jet change 22/06/23【summary】

This time, we have changed the ignition timing of AS Uotani SP2, and the tuning is highly praised.
If you advance the ignition timing, it will give you a pseudo-feeling, but it will give you a feeling of leaning overall.
Lately, I've been tuning it to a richer tuning and trying not to get caught up in the air-fuel ratio meter as much as possible.
I am tuning up FCR.
We didn't just replace jets haphazardly, we did things we had never done before.
I feel that if I try to incorporate even just a little bit of it, I will be able to discover something.
The big thing recently was that the needle on the vacuum gauge was out of alignment.
In addition, I was only thinking about the range of MJ's influence so that it would have a slight effect at around 1/2 throttle opening. If you increase the value by 10, it will change dramatically.
I noticed a lot of things about myself.
Next time I'm planning to mainly touch on AS, but at the same time, it's a little difficult to understand the effectiveness of PS, so I'll try various things on my own as an experiment.
See you again!
Copied title and URL