Don't know on my '88 Honda 350 Fourtrax, but I'm the second owner and have had it since '95. I put a lot of miles on it every year - mostly in the mountains, but it is my work horse on the farm, also. Only been in the shop once because the kill switch went bad and kept it 'killed' all the time. I change oil yearly and clean/oil the air filter twice a year. The Honda dealer keeps asking me when I want to trade it in on a new one. I told him if he would sign a contract to the effect that the new one would be as tough and last as long as my machine, I'd trade in a heartbeat. Obviously, he refused.
The Dunlop tires I have on it have been great. They were new in '95 and I can get one more year out of them.