"Duane Bozarth" wrote in message
...
Doug Miller wrote:

In article ,
wrote:
Doug Miller wrote:
....
The suspended solids in used engine oil are, for the most part, fine
particles
of metal. The junk that collects on the bar during use is wood dust.
Surely
you don't imagine that the two produce the same degree of wear on the
chain
and bar.

A lot of the chips and dust are wood, but a lot isn't--the inevitable
dirt and other grime is at least as abrasive as the much smaller
diameter particles that made it through the engine oil filter...after
all, you wouldn't be particularly concerned to run your auto another
500
or even 1000 miles above the 3000 mi mark if you were on a trip and
needed that to get home for a more convenient oil change, would you?
The lube requirements of any modern engine are far more onerous...

Just the same, it should be obvious that you're not doing your chain saw
any
good by running used motor oil through it.

By the same token, I don't think it at all obvious there would be much
difference observable one way or the other as opposed to clean motor
oil...

Seems to me like the "stale gas" thread or the "diluted 2-cycle gas in
4-cycle engine" threads of recent history...

Duane,
I've got a 25 yr. old Poulan that has an 18 yr. old bar. I've used the
hell out of that saw on_big_trees over the years. Only reason I changed the
bar was it got bent when a tree pinched it when I was cutting on a hillside.
I've always filled the bar oil tank with used motor oil. My chains last a
long time and it should be evident that it sure didn't do any damage to the
bar. I do pump the oiler quite a bit on the saw and keep the bar well
lubed. Now................................wait for it.
Some horse's ass will tell me I'm spreading carcinogens to the little forest
creatures who might come and lick the stump that has used motor oil on it.

Garrett Fulton