You can feel some changes. You will be able to feel a stronger or weaker pull, better or worse response and the sound the carb makes can also help. Once you get to a point that feels good though then you still need to look at the plug and monitor temperatures to tune finer than what your backside tells you, you can can still be dangerously lean. Try the 95 jet. I have run 92 and 95 with minor difference. If you are too rich, you can try to drill your other or just put the 90 in for a back to back comparison. Many riders run temp gauges to use as a tuning tool as well. Hondas run hotter than others and temps in the 400-450 range are the acceptable max.