I am the owner of a Honda motorcycle [CBX1000] who lives in Hiroshima City, Japan. I am posting about FCR carburetor and CBX1000 customization. I also post about things other than cars and motorcycles. We will post information that will make bikers around the world happy.
FCR Tuning – Tuning throttle opening from 1/16 to 1/8 – 2022-11-06
Regarding the current FCR tuning of CBX1000, I was concerned about the lower throttle opening. It is very bad to get caught up in the air-fuel ratio meter, 10.5 is a partial between 1/16 and 1/8 throttle opening. It is unclear whether this condition is good or bad. It's not that I have a hard time riding the CBX1000 or have any complaints. My CBX1000 emphasizes acceleration and the acceleration pump does not work at low throttle openings. I'm trying to tune it so that I get a good feeling of acceleration when I open the throttle. I decided to try out various things, so I tried various things this morning. It is best to touch the lean direction with the throttle opening around 1/16 to 1/8. Let's start!
I tried various things
As a prerequisite, the jet needle will not be changed. ① Adjust with air screw ② Set the number of clip stages to one level lean ③ Change slow jet from 48 to 45 ④Change the discharge timing of the accelerator pump ⑤ Adjust with pilot screw
I tried the above 3 points. Try out multiple options and choose the best. On the other hand, if it gets worse, the current tuning will be the correct answer for you.
① Adjust with air screw
It is effective. Looking at the numbers alone, it has become slightly leaner. Since it is necessary to turn the screw a lot, it seems better to tune it in combination with a slow jet. It doesn't seem to be good because it feels too light at around 1/8 to 1/4 throttle opening.
② Set the number of clip stages to one level lean
90FXM#3 → 90FXM#2 → 90FXM#3
If you just look at the numbers, it seems like it meets the requirements, or rather, it's better. However, I don't really want to use it because it completely changes the ride feel. It feels like it's accelerating a little too much now. Since the acceleration was a little mild, I returned to the original number of clip stages. It is meaningful to include adjustment of the straight diameter.
90FXM#3 and 90FTM#1 are equivalent. 90FTQ#1 It is also possible to change to a jet needle only from autumn to winter.
③ Change slow jet from 48 to 45
It didn't have much effect. On the contrary, I felt that the sense of acceleration was lacking. It might be a placebo effect. In the case of CBX1000, it seems better to determine the lower diameter while adjusting the straight diameter of the jet needle for larger numbers such as 48 or 52. This is a tuning that gives a sense of acceleration.
④Change the discharge timing of the accelerator pump
I tried to get there early and did a test drive. It got worse. It made the ride very bad for me. Rejected.
⑤ Adjust with pilot screw
It is effective. It's the same as touching only the air screw, but it affects everything else. You need to touch it in moderation.
For FCR beginners – Essential habits when replacing jets
There are two things you should get into the habit of doing when replacing jets. Be sure to check the number. Those riding multi-cylinder motorcycles should be especially careful. I put it in a case based on my preconceived notions. It's possible that the jet was actually a different number. please note. The next thing to check is to make sure the jet is not clogged with debris before installing it. Just a small hole letting light through is enough. The slow jet and main jet have small debris. It may get clogged. If you install it without realizing it and it is clogged with dust, it will be very troublesome. The condition of the motorcycle becomes worse. It's good if you notice it right away, but if you don't, it's a disaster. Troubleshooting takes a lot of time. A little effort will save you a lot of time. Please make it a habit.
FCR Tuning – Tuning throttle opening from 1/16 to 1/8 – 2022-11-06【summary】
I feel that the correct answer is to change the straight diameter. About jet needles, Since 90FXM is a special order product, other straight diameters cannot be selected. In the same way as above, I'm thinking that it might be possible to change to 90FTQ#1, 90FTR#1, or 90FTS#1 only from early fall to winter. Originally, the jet needle was not sharp enough, so I contacted BITO. The early jet needles of the FCR sold now are different from when I purchased them. The tuning theory is to make it rich in winter. The summary is to consider tuning including changing the jet needle. Lately, I've been focusing too much on one jet needle. Jet needles should be changed frequently depending on your mood. The reason for this is that it is designed for easy access. On the other hand, for the main jet and slow jet, you have to touch the chamber, so You will definitely end up spilling gasoline. There are some aspects that are contrary to the eco-friendly ideas of today. As for the main jet, it is not a hassle, but the slow jet is a category that requires a lot of effort to replace. There are other hassles other than replacement, such as adjusting the throttle wire, adjusting the idle stop screw, and checking synchronization. There is no problem with the current tuning. I'll use some more time for test runs. I will also try changing the jet needle based on the results. Well then, everyone, please enjoy your FCR life! See you again!
