I've got a couple of guys with ridiculous hours on their 372's..... but I see them for cleaning and maintenance fairly regularly as they get used hard. I've seen 2 or 3 other companies that can't seem to keep a saw on the truck long enough to get dirty. Guys can't seem to figure out how to get an air filter back on properly or make sure the gas has oil in it.....
Maintenance Definitely more than 200 hours though.
I've got some guys that never even look at the air filter. They're so packed with sawdust that you'd think they troweled it in.
Preventative maintenance is pretty rare with most guys. Most will run the saws until they have an issue, then bring it in. Hopefully, before any serious damage occurs. A lot of the tree service saws come in after some gravity induced trama. It's really amazing how much abuse a saw will take and keep running.
But guys that take care of their saws generally get 2-4 years out of them. Sometimes more. These are guys that I say have "good ears". They can hear when the saw is running different, and they bring it in to have it checked. They clean their air filters, pay attention to their fuel cans.
Good call, got a real good buddy, now in Oregon timber faller and they are moving put a lot on the ground. In some big wood too, and he is hard on saws. Ports em and does some work on his own saws. 66o's siad he gets 6 months to a year. Said about 6 months some are losing power, and rattling pretty good. But want to say some get a year, and never met anybody harder on saws, so that's pretty good. Also remebered he was going 6-7 days a week.I know a stud faller out west that runs mostly modded 660's ..
He says he can wear out a 660 in a year. so figure roughly 30 Hrs a week run time X 50 weeks around 1500 hrs for him and the saw needs attention, Usually piston bearing etc... assuming it dosnt get smashed before then.