FCR Tuning - Tuning that becomes worse due to jet changes is within the acceptable range of effects....
What does it mean to tolerate poor performance? I will write about the tuning that makes the performance worse. FCR tuning is a repetition of AB testing. If there is no change even after adjusting the carburetor, it cannot be compared. It is possible to get a result that there was no change, but if you cannot compare, you cannot tune the FCR.