Caution - guessing may lead to damage
I was wondering IF and WHEN this would show up on the FZ8 Forum. Caution. This involves adding/removing more EFI fuel injector pressure.
When I saw this video the first time, I did some homework on it and found some procedures for it for other Yamaha bikes. The process works in the same type manner for FZ1s, FJs and other bikes in the same build timeframe. The problem with doing this is you are guessing (without dyno testing) and need to be sure you repeat it for all four cylinders. The values span something like -123 to +126. This value can and should be be set on an individual cylinder basis; 1-4 on the right side. Be careful to only set just one cylinder, there are three more to go. On the other bikes like FJs, you have to cut some wires in the harness and ground one to make it work effectively. If you bring your bike to the dealer and these are off, they will likely see it, question it, and/or reset it not knowing.
I would not make these changes unless I had a dyno with AFR/EGT sensors to measure changes immediately. The range can vary on different bikes.
By the time I figured out what this EFI scale change does or does not do in diagnostic mode, my conclusion was to go ahead and buy a Power Commander since it adjusts other elements than just the EFI control changes through the dashboard.