CBX1000 FCR main jet full throttle tuning

CBX1000 FCR main jet full throttle tuning

How do I tune the main jet of the FCR?

I don't have an air-fuel ratio meter so I don't know...

I won't know until I put it on the Dynojet and measure it...

I'm going to write about the way I tune the FCR of my CBX1000.

I haven't put it on the Dynojet, but I have an air-fuel ratio meter installed and I drive on the highway.

I don't think I've seen any articles on the web that specifically write about full-throttle tuning of the main jet for large motorcycles.

I don't know if my method is correct, and I don't know if I'll be doing it the same way next year.

At least for one CBX1000 in Hiroshima, I tune the main jet of my CBX1000's FCR as described.

I think it's easy to reach 200km/h.

I can't write that it's easy to reach 200km/h, so please understand (lol)

Tuning is based on acceleration

This may just be my current preference, but I decide on a starting throttle opening and then judge the tuning based on whether the acceleration feels good or bad when I turn the throttle up to a certain throttle opening.
I try not to look at it when it's partial (when the response is settled).
I consider it good as long as the air-fuel ratio during acceleration is in the high 12s and the acceleration feels excellent. I use the air-fuel ratio gauge as a guide for deciding whether to change the jet to rich or lean when the engine isn't running well.

When changing the main jet, the throttle opening changes from about 1/2.

I feel that changing the main jet also changes the feeling of acceleration from about 1/2 throttle opening.
If the feeling of acceleration from about 1/2 throttle opening to about 3/4 throttle opening is good, there is a strong tendency for it to improve at full throttle as well. This change occurs when the jet needle reaches the end of its clip stage.

Driving at full throttle on the highway

I'm talking about the CBX1000.
I'm trying gears [4] and [5].

-Throttle opening from 1/2 to 3/4.

-Throttle opening from 3/4 to full opening.

-Throttle opening from 1/2 to full opening.

How much does the speed increase from full opening?

I'm looking at the main jet number using the above method.

Gear [3] revs up in an instant.

Gear [4] also revs up fairly quickly.

Gear [5] is too fast and feels a little dangerous.

Once you exceed a certain speed, the speed increases steadily.

I look at the main jet number to see if that increase is good or bad.

I've tried a few processes, but it's difficult to try it all the way to full opening,

so I'm using a main jet that has many good points.

I think a slightly richer number will give you a more fun main jet with a greater sense of acceleration.

Caution when installing AS Wotani SP2

Please set a rev limiter. My CBX1000 hasn't broken even with the dial set high. In my case, I have the dial at [6] and the upper limit is 10,200 RPM.
If you set the dial to [0], you won't be able to use all of the power. The CBX1000 accelerates further once it exceeds 6,000 RPM and once it exceeds 9,000 RPM. I don't know if it will accelerate further once it exceeds 10,000 RPM, but it feels like it's getting dangerous.
It's easy to tell when the rev limiter kicks in.
It passes the red zone at 12,000 RPM.

Oil temperature rise during full throttle driving

My CBX1000 has a standard oil cooler. Although it is due to budgetary constraints, I prefer smaller oil coolers because they make the engine more noticeable.
Ideally, a larger oil cooler should be installed.
When riding with the throttle fully open, the oil temperature on my CBX1000 rises to around 100 degrees.
It's not very pleasant when the oil noise gets too loud.
Oil temperature also varies depending on the type of motorcycle and each individual motorcycle.
The oil temperature rises quickly when the engine is revved at high speed.
The oil temperature rises with the engine speed rather than the speed.

The main jet size should be in two stages or one stage.

This is assuming the wheels are in generally good condition, but I would change the club number by one or two steps.
If it's hard to tell whether the wheels are in good or bad condition, try changing the club number from rich to lean, around 4th position.
If you feel that the acceleration is lacking, then that club number is the limit.

Changing the main jet at a service area on the highway

The main jet can be easily changed by removing the drain bolt. Gasoline will leak out when doing so. Also, if you have trouble with the gasket of the drain bolt, you cannot easily get a replacement at a hardware store like you can on regular roads. It is necessary to prepare a spare gasket and a measuring cup or rag to catch the gasoline. It is best to avoid disassembling your motorcycle at a service area on the highway. It is best to get off the highway and change the main jet.

FCR – For beginners – It’s okay to change the main jet just once, so give it a try.

You only need to try changing the main jet once, so I would encourage you to give it a try.
You will learn the subtleties of how FCR works. Be sure to change it with the fuel cock off.
Riders who aren't particularly interested in DIY can just leave it to a shop each season.
You can ride to a certain extent even with a maintenance-free FCR.
It doesn't take that long to change the main jet.
Even if it's your first time, it shouldn't take more than two hours.
Additionally, changing the clip stage of the jet needle is not difficult, so please give it a try.

CBX1000 FCR main jet full throttle tuning【summary】

It is dangerous to tune the main jet on the road.
I feel like you could easily get 200km/l.
I have written my own thoughts on selecting a main jet.
Please be careful not to go too fast.
See you again!

*A photo gallery of the CBX1000 is posted below.

CBX1000 Photo Gallery

I picked up some images from the past logs that seem to be related to the FCR main jet.