My DL 1000 was barely tight on 1 exhaust valve at 30,000 miles, the first check I did. Shimmed it and left the others alone. It probably would have been fine without adjusting. At 50,000 miles, the same tight valve that was re-shimmed had opened up a little, about half the clearance I had shimmed it tighter at the first check (and why I think it could have been left alone the first time). I never checked it again and it is over 100,000 miles now and running fine.
I too have a quad. A Honda Rincon. On this machine, I checked it at 1,000 miles, past the factory 600 mile recommendation and it was in spec. At 5,000 miles I checked again (mostly because it is so easy, not the case on a DL engine) and the intakes were very slightly loose. It now has 12,000 miles (a lot for an ATV). Most quads use rocker arm valve trains and they tend to move more than the shim under bucket valves that most high rpm bikes use.
A modern shim under bucket valve train wears very little. I recommend a check around 30,000 miles and if they are anywhere in spec, put it back together and think about other issues like global warming or meteorites hitting your garage.
There are many tales of screwed up valve servicing on these bikes and none I am aware of that have burned a valve seat. Loose valves will tick if you have a good ear. Tight valves will be silent, but the bike will typically pop on deceleration and show signs of slow starts when hot.
If it means anything, I used to wrench in a multi-brand motorcycle shop in my youth. I changed careers to something less aggravating. I am an OCD nut about using synthetic lubricants and OEM parts. I obsess over my bikes, I sleep with a torque wrench under my pillow, but tend to leave the motors alone unless necessary. YMMV
"If its not broke yet, it can still be fixed"
Last edited by STCorndog; 08-11-2018 at 10:27 PM.