I’m curious how you’re measuring RPM with a sensor on a fuel line.
Is the older (pre-2019) model BX23S a hydrostatic or gear drive machine? If hydrostatic, there could be quite a bit of error in PTO RPM and Engine RPM because of loading and efficiency of the hydraulic motor for the PTO. Probably not enough to worry about on most applications, but a generator may have some issues with frequency if the PTO speed fluctuates with load. The governor controls engine speed, not PTO speed. It might be worth checking your PTO speed under impact loading or heavy load changes, especially if you’re using it for speed sensitive loads. There’s a certain amount of ‘slip’ when mechanical energy is converted to hydraulic energy and back again, and that can vary considerably with load and age and adjustment of the swash plates. With a gear driven (clutch operated) PTO, it’ll be a pure gear ratio.
I’m not dissing your tach at all. I like it. Anything that gives more instrumentation is a good idea.
The LX display comes with a 3 position Tach, engine, mid mount, and rear PTOs. I kinda wish Kubota would have put all three on the same display, but they didn’t ask my opinion before I bought one. The SU model (the one I have) always reads 0 for the middle PTO because there ain’t one. Not sure why there isn’t a slight firmware difference for the SU(to skip the MM PTO), because it’s really a whole other animal from the CAB or ROPS models. I like the empty seat bypass too. No need for secret handshakes or having to put the seat up, but I do anyway because I don’t like to fill it up with dust, or frying my bacon when I get back on it. Just lock the brakes and hold the bypass for 5 seconds and you’re ready to hop off. You can engage and disengage the PTO from the ground then. I also put the range selector in Neutral just for additional safety though it isn’t required. One little bump on the treadle or unlock the brakes and it’ll shut down. I make sure to test all the safeties at least once a month. I feel a lot safer operating my LX than I did on the old 8N and Farmall I grew up with.
One thing I really like about Kubota is that they value and implement customer feedback on their products