AS Uotani SP2-Dial tunings

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AS Uotani SP2-Dial tunings

My CBX is equipped with AS Uotani SP2.
The first thing I want to do is not strengthen the ignition system.
The reason is that we don't want to cause trouble by removing old genuine products.
Another reason is that AS Uotani SP2 is great as an aftermarket part.
One of the weak points of old motorcycles is the ignition system.
AS Wotani SP2 solves this problem at once.
Another thing that makes AS Uotani SP2 very reliable is that it is hard to break.
Regarding the ignition map, depending on the car model, it seems that the 3D map ignition timing can be set by interfering with the throttle position sensor.
Unfortunately, it seems that CBX does not support this. It will be operated on a 2D map.
The reason I learned that CBX does not support 3D maps from the throttle position sensor is
This is the result of calling AS Uotani and asking.
As for the 3D map based on the throttle position sensor, it may be possible to provide support over time, but there seems to be little hope.
Do you go out of your way to write blog articles with titles like this?
The other day, I had a chance to read the manual again.
At that time, there was a statement that said it was okay to touch the dial intuitively, so I will write about the results of my touch.
In my blog, I basically write about CBX as my history.
I myself have been indebted to someone in the past.
We hope that by disseminating information, everyone who rides a motorcycle will benefit.
I would be happy if I could be of any help.
I would be happy if the world of motorcycles became more exciting and benefited me as a result.
This should be helpful for riders who are considering installing AS Uotani SP2 on their CBX.
Reviews of motorcycles that have already been installed are very helpful for riders who are considering installing it. This is a long blog post, but please read it.

Two dials of AS Uotani SP2

The ignition timing is indicated by 10 increments from 0 to 9.
[0] is the basic value. Advances the angle by 2 degrees from [1] to [4]. [4] is +8 degrees.
The angle is retarded by 2 degrees from [9] to [5]. [5] is -10 degrees.

The one with 16 steps from 0-F has a rev limit that applies a limit according to the rotation speed.
This is a helpful feature when you accidentally run the engine at high speed without looking at the meter.
[0] is 9400 and the rpm increases by 200 rpm. [F] has no limit.

right dial

@Controls the ignition timing. The way to tell is by the 10-level scale on the dial.
[0] Basic at 0 degrees [1] +2 [2] +4 [3] +6 [4] +8 [5] -10 [6] -8 [7] -6 [8] -4 [9] -2

left dial

@The limit is set based on engine speed. The scale is 0-F with 16 hexadecimal levels.
[0] 9400 [1] 9600 [2] 9800 [3] 10000 [4] 10200 [5] 10400 [6] 10600 [7] 10800
[8] 11000 [9] 11200 [A] 11400 [B] 11600 [C] 11800 [D] 12000 [E] 12200
[F] Limit off


Excerpt from the manual that seems necessary for this story. There are some parts that are shared with AS Uotani SP2,
It seems that the design is specific to the vehicle model, so you may not be able to understand the dials etc. unless you look at the manual specific to each motorcycle.
There are some important things you may miss if you don't read carefully.
Excerpt from 2P to 3P as an example
- Regarding the description of 1350 rpm in light switch [1] -
There are also things that are common to other switches.
・Be careful of knocking at full throttle in [3] and [4].
It says that there may be knocking around here.

There is no problem if you read them carefully in order, but if you skim them, you may miss something, so please read them carefully.

AS Uotani SP2 ignition timing

I thought it would be better not to touch the AS Uotani SP2's dial too much.
When I read the manual, items [2], [1], [0], [9], and [8] did not seem to be particularly dangerous to touch. If the angle is too advanced, it will knock, and if it is too retarded, it will cause abnormal combustion and power down.
Either way will cause the engine to blow.
A few years ago, when I tried tuning the dial to [1] and [9], there was a change, but I couldn't judge whether it was good or bad, so I returned it to [0].
After some time, I felt that [2] and [1] were good, and [9] and [8] were bad.
[1] feels like you can ride it as is, but [2] looks like it will feel better if you touch the clips and screws.
It's a feeling.
Currently, the tuning is richer than the tuning a few years ago, which is my preference.
I feel that by advancing the dial, the carb tuning has become leaner. It's not just thin, it's thin with a sense of power, and it feels like it's one step stronger. On the other hand, when I retarded the engine, it felt sluggish and I immediately decided that it was no good. The best ignition timing for advance angle is just before knocking.
If you go for the limit, you're likely to end up breaking the engine, so
For the time being, set it to [2]. I tried up to [4], but in the end I will reconsider either [2] or [3].
The reason for adopting [2] is that we want to leave room for advancing the ignition timing. It's also written in the manual, but [3] and [4] say to be careful about knocking when fully opened. [2] is interpreted as the ignition timing with a safety margin remaining.

Determining fuel condition with AS Uotani SP2

This is a summary of this blog post.
I was wondering if I could judge whether the current tuning is strong or light by touching the ignition timing dial of the AS Uotani SP2.
You shouldn't judge based on the dial of AS Uotani SP2.
However, if there is a change, it may be possible to determine whether the FCR tuning is high or low.
It may be that the appropriate advanced ignition timing is determined for each engine.
It is necessary to adjust the tunings for each ignition timing.
I felt that it was impossible to make a judgment unless the original tunings were in good condition.
I feel like if I have a good tuning and just touch the ignition timing dial by one step, I can more clearly tell whether it's good or bad.
However, I felt that it was not a good idea to turn the dial too far.

AS Uotani SP2 rev limit

This is a story only for CBX. Until now, I had set the limit to [0]9400,
CBX's red zone starts at 9000, so even if you limit it at 9400,
The power of the CBX's high-revving engine still has plenty of power, or rather, more power.
It seems to have reached a plateau at the point where the power is produced.
That doesn't mean there is no limit for [F], but
I set it to 11400 with [A] and reset it to the maximum value of the meter.
This is not the end of the story, but from now on, we will lower the price periodically.
When I think about it carefully while writing, I realize that it is a situation where the engine is revved violently.
It's very scary because I feel like I'm going to destroy the engine in no time.
It is a motorcycle that is difficult to reach the point where you can run faster than anyone else.
When I run with someone, I think I need this number of revolutions to keep up with them up to a certain area.
I would like to set a limit number based on how far I can keep up with a fast motorcycle. Until now, one of the reasons for not being able to catch up with faster motorcycles was the rev limit.

Test drive video on YouTube

I took pictures of each dial to compare the changes in fuel tone.
It is difficult for anyone other than the person taking the measurement to understand.
This time I will only post [2] and [3].
This is a running video of about 3 minutes.
In the future, we will consider ways to publish it, such as adding more explanation.
I also tried [4], but the engine didn't break.

Photo of CBX-AS Uotani SP2 being set up

I don't have any photos that are particularly impressive, but I'd like to post them just in case.
The dial sets the ignition timing to [2] and the rev limit to [A].
If the dial knob breaks, you can send it to AS Uotani in Shimonoseki and they will repair it at a relatively low cost.

AS Uotani SP2-Dial tunings【summary】

I took a quick look at the dial tunings, but it should be used when touring or running long distances.
You should look for the appropriate ignition timing dial for various speed ranges.
There are three discoveries that I think were good for me.
The first is that the rev limit has no meaning unless it is set at the appropriate position.
Although it is an old motorcycle, it is a 1979 motorcycle. It can easily reach 200km/h. Since it is a commercially available car, there should be a somewhat large safety margin. When I was riding at [0], I stopped thinking.
It is a mistake to open the limit to the limit.
However, I realized that it would be a problem if I didn't release it to a certain extent.
Second, I thought that I shouldn't touch the ignition timing, but I thought there was no problem even if I touched it a little.
That's what I mean. The engine advance angle becomes a problem when it exceeds 20 degrees from top dead center, and at 25 degrees it almost knocks. I think it was written somewhere that the advance angle that causes knocking is different for each cylinder.
Even if the engine is advanced by 2 or 4 degrees, it is unlikely that the engine will blow while driving around town.
That doesn't mean you shouldn't do anything unreasonable.
There is no problem even if the ignition timing is changed slightly.
The third is that ignition timing may be used to judge fuel condition.
There are factors that can be used to judge, such as the heat value of the plug and the high octane and regular gasoline.
It is an element that is easy to judge because changes occur just by touching the dial.
Of course, this is not a method exclusively for making judgments, so it is prohibited to make judgments by excessively touching the ignition timing.
It may be helpful to change the ignition timing while trying out the tunings and see what happens when making a decision.
The best answer is to keep trying until it breaks.
If you are a researcher or a professional mechanic, you can try it until it breaks, but
You can't try it out as a general user until it breaks.
There are many things that I have only been able to roughly test, so I will try changing the ignition timing and riding for the time being, keeping in mind the safety margin. See you again!
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