I will confess, I have owned my current ride a 2000 KTM 300 EXC for 3 years. During the time I've owned the bike, I've done the top end (piston, rings, needle bearing, replaced clutch plates, wheel bearings (front and rear) and replaced the juice in the hydro clutch, and replaced the fluid in the brakes front and rear, and replaced the brake pads.
All of the above was done during the off season, all I consider normal maintenance. I've yet to pull the swingarm, although its on my list for the off-season. KTM does not have linkage suspension; they use an F-bushing. Plans are to pull the swingarm, replace bearings as needed, check F-bushing, replace if needed, and grease everything. I'm not sure if I'll get to the steering stem.
During the season I replace the gear fluid 2 times, and clean the filter after every 6th ride.
I need to get the above done, as I need to do the top end on my son's quad. Yes, not only is he a quad turd, but he rides a 4 stroke... (Honda 400EX). When we purchased the quad used, (two years ago), knowing it needed new rings, and valve seals. So its time to tear it down, and replace the top end.