Not according to the Kubota WSM. They do say check them every 50 hours but the first scheduled change is at 500 hours.
Of course it doesn't
hurt to change them but at Kubota's price I'll wait until I see contamination, but probably not 500 hours, maybe 200 or so
As for removing the cowling, you have to take off the bumper..they apparently have a gorilla on the assembly line installing that bumper, I had to use an impact wrench to bust loose those socket head screws holding it on, thought I was gonna break my 10mm allen socket. I could not bust em loose leaning on a 1/2" drive ratchet, and I weigh 250 lbs!
Actually according to my copy of the WSM it states to check the fuel filter element every 100 hrs starting at 100hr service.
The section on checking the fuel lines and the fuel filter element reads like this:
The fuel line connections should be checked annually or every 100 service hours, whichever occurs first.
1. The fuel line is made of rubber and ages regardless of service period.
2. After inspection, if the fuel line and clamps are found damaged or deteriorated, replace them.
3. Check fuel filter. If it is clogged by debris or contaminated by water replace it.
There are some cautions and notes I left out for clarity.
So this begs the question if you are going to disconnect the filter from the fuel line to check it for debris or water, then I would just replace it. So that means to me, do an external check of the fuel lines and fuel filter and if the tractor is running fine then change the fuel filter every 500hrs.
About the 50hr service, the only things marked for service are the following:
Engine oil : Change
Engine oil Filter : Replace
Transmission oil Filter : Replace
Transmission fluid : Change
Engine Start System : Check
Greasing : -
Wheel bolt torque: Check (front wheels - 110-132 ft-lbs, back wheels - 80-96 ft-lbs)
That's it.