I wore out a few weed eaters as a kid. I had a lawn care business from the time I was 14--19yrs old. I always used some cheap old Wal-Mart 2-stroke oil because I was a kid and it was cheap. It took about 4 years of hard running to wear out a couple Ryobi trimmers. All they really needed was a new set of rings, but we didn't have the internet in those days and it was cheaper to just buy a new machine than screw with an old one. I had grass to cut and money to collect. Too busy to fuss with a weed eater that didn't owe me a thing after so many years of abusive service.

They were carboned up in the mufflers. Those spark restrictor screens and tight mufflers collected a lot of soot and carbon. I was mixing my oil at 32:1 and they smoked like hell--but it was cheap oil, don't forget that.

I could venture a guess on how much time was on those machines. Probably 1hr a day for about 150 days a year x 4 yrs. Whats that? About 550hrs on a weedie engine that I never cleaned or did squat to it. Just put fuel in them-- spark plug once a year-- and ran the snot out of them.

Those are cheap engines too. I would think a higher quality chainsaw engine (Sachs based - Brison, FPE, Fox, Taurus, Zenoah etc..) would last at least 3 or 4 times that long if you kept oil in it and didn't smack it into the ground.

If you read back through my posts in this forum, you will find that I've been telling people the brand and type oil doesn't matter. Pick one and mix it according to the label--run it. I've been saying that for years, but not many will listen. They just keep drinking the Kool-Aid and buying the Super Duper Turbo Prop Twister Synthetic oils that cost $20 a quart because they think it will make their engines last longer.