Hello good forum people! The kubota recommendation for replacing this filter is 2 years. My machine is way older, but this last time I cut, the mower was running rough (meaning that the engine was surging and it seemed like it was getting too much fuel). When I increased throttle the engine lagged before it caught up and then didn't seem to run at full throttle. I have since bought a cheap tach. I'm in the early stages here of troubleshooting, but does anybody replace the carbon filter? (It's pretty $$$)! And could it cause/contribute to the running conditions described? Thank you from the free state of Alabama.