Thanks for the ideas folks. I know I could reduce the emissions with
other fuels. But she should not be in this region in normal running.
Anyway I went to check valve clearances and compression. Found that
couple of low clearance values ( yes I did do this cold) and that the
push rod was sticky to turn ( well grunchy may be a better term) when
the valve was closed. Seems there's some wear on the ends of the rod.
(could be more than one).
So what's the likely hood of cam and/or valve damage. Plan to pull and
check tappets tonight (need that little magnet tool, my magnet is too
big) for wear. Also will reset valve clearances and run to check
compression when warm. Engine runs fine otherwise.