If there isn't water, or other debri visible in the bowl, the filter hasn't change color dramatically, and your tractor's power is normal, I'd leave it alone for a while. A fuel filter with 100 or more hours on it, is a much more efficient filter than a new one.
As far as the manual suggesting a cleaning of the filter every 100 hours.....that's nuts. If I'm going to take it apart, it's going to be changed.
Like someone else said.....unless you've had some crappy fuel, your filter will go far longer than 50 hours. Changed my CK's the first time at 275 hours, and didn't really need to then. Haven't done it since....now at 561 hours. I might add that I do use Power Service additive, and faithfully treat every gallon of fuel, winter and summer.