Because the speed can vary so much on these OHV"s most MFG's service intervals go by engine hours or miles which ever comes first.. but generally the hours are first... The break in at 20hr, every the 50hrs a/f then every100hrs after that. Doing your services at or close to the every 50/100hr mark even if the first is a little early makes is easy to keep a mental note...I have always documented what I did on the blank page in the service manual found in the glove box. So you have a record of what was done last at what date. Its a good practice to take the time to give it a good look over every time you wash it or after every use. Take the time to replace or repair the damaged and worn items as soon as you see them and you won't have as many problems on the trail..
Here is the schedule for the krx.
Here is the schedule for the krx.