I've put a little over 100 hours on my 150 since purchase in January
'03. Recently, I've begun oil analysis with Blackstone. The universal
avg for copper on an O-200 is 9 ppm. My reading at 488 hrs on the
engine was 18 ppm and my most recent reading at the last oil change is
even higher at 25 ppm. I thought that the former 18 ppm was a
byproduct of having all of my exhaust valve guides reamed. I did this
because I was experience sticky valves. Reaming the exhaust valve
guides has cured that and it was my best guess that doing that caused
the 18 ppm reading. Now, I am getting 25 ppm in copper and there
hasn't been any service on my engine. I cut the filter open and it's
very clean. I know I'm not making metal. I'm a little worried but then
I found this link:
http://www.prime-mover.org/Engines/G...es/Copper.html

I use Aeroshell 15w50 -and- I've been using TCP additive in my fuel as
a lead scavenger. I'm no chemist but I think the TCP the article above
refers to is the same or very similar chemical as Alcor TCP which I've
been adding to my fuel. I plan to stop using the Alcor TCP and switch
to a single weight oil and see what happens. Would you be worried with
this reading? Does the article I linked to seem credible? I know it's
not recent. Also, if TCP in the oil can leach copper, wouldn't it be
able to get into the oil if used as a fuel additive?