I do my own. The regular yearly maintenance is super-easy. Depending on your engine skills, you may choose to take it to the dealer when bigger items come up (head removal for carbon cleaning, etc.), but those items happen on decade-long time scales (2000 hours) for home-user profiles.
Here's my yearly maintenance:
- Wash the mower at end of season, then stick it in a heated/conditioned garage space long enough to be sure everything is dry for winter storage.
- Throw down my 2-piece RaceRamps (TM), and drive mower up onto them.
- Remove lower section of RaceRamps, for easy side access under deck.
- Remove rear engine guard from mower.
- Slide oil pan under engine and open oil drain while engine is warm. Also spin off oil filter and drop that in the pan.
- Remove air cleaner cover and blow out air cleaner with compressed air (outside). Replace if due or needed.
- Pull out the manual to remember all the grease points, and grab a grease gun. Grease all 10 or 11 points (3 spindles + 4 mower hanger blocks + 2 brake pivots + height adjust.
- Wet new oil filter o-ring, and spin it onto engine.
- Close drain and refill with 90% of sump capacity. You won't be able to check with dipstick until you have the mower off the ramps.
- Remove blades with 1/2" air impact or similar, and scrape underside of mower deck clean. They make special rounded flexible putty knives for this, well worth your $11 or $13.
- Wipe a bit of antiseize compound on blade bolts, these things are always damp, and get nasty without it.
- Grab spare set of blades out of storage, sharpened at some point prior to this, and install. Run bolts in by hand to be sure blade seats neat and clean on boss, then snug with a quick squeeze on the 1/2" air impact driver. You obviously want the blades snug, but don't go full-gorilla on these, it only makes them harder to remove later. Blade spin direction is usually designed to ensure these bolts can never spin loose on their own.
- Back it off the ramps, shut down.
- Check pressure on all tires and adjust. Debug/tube/replace any tire showing abnormal air loss.
- Check dipstick, adjust oil level as needed.
- Park it in the shed, connect BatteryTender or other similar battery maintainer. Ready for next season.
Ignoring the washing, which usually happens separately from the rest on the day of last mowing, all the rest of this probably takes me 60 - 90 minutes, with the biggest variable being the mower deck scraping.
If you take it to dealer for service, you'll still want to do the scraping and washing on your own. They usually just change fluids and grase zerks.