My '81 started running crummy shortly after my last oil change. It
sounds a lot like a valve sticking, with lots of snapping and popping
and low power. I thought maybe it was ignition, but replacing the cap,
wires, etc. didn't help, and I've got pointless ignition.
   I'm wondering about the oil, since what I usually use if straight
50wt Castrol in the summer, but couldn't find any, so got 50wt. Kendall
instead. So I was wondering if that could have gummed up a lifter or
something? It's clearly #3 that has the problem, so I pulled the valve
cover, got it at TDC for #3, and loosened up the rockers -- yes, I know
it's no clearance and then two turns to adjust -- but what I saw with
the exhaust valve was that with the adjustment all the way out, there
still was no freeplay for the rocker, like there was for intake. So I
re-adjusted those two, then put the other cylinder up to TDC and
unscrewed those -- both had freeplay. Adjusted those back to specs, and
put the cover back on, and started it up -- very  little snapping and
popping, but still some.
    Haven't done a compression check because my wife's away and can't
hold the guage on there and crank the engine at the same time. So what
am I looking at here -- a burnt exhaust valve??

--
Harmon Seaver hseaver@harmon.bml.usouthal.edu
http://harmon.bml.usouthal.edu
=======================================================================
All is impermanent, but this too shall pass away, and the way of the
Samurai is death -- so speak your mind now, or forever hold your peace.
=======================================================================
Copyright, Harmon F. Seaver, 1998. License to distribute this post is
available to Microsoft for US$1,000 per instance, or local equivalent.
=======================================================================