On May 29, 9:17 am, Capt John wrote:
....
Before pulling the injector pump, I would get the injectors serviced.
Injectors tend to go long before the pumps do, and they tend to be the
source of most smoking problems.

Fair enough. I had the injectors out not all that long ago and they
were fine, but they are usually easy to pull on these little Yanmars
and if we're out of commission anyway I will have them looked at
again. The other problem with air getting in (or, as Larry has it,
fuel getting out) isn't likely to be injectors. At ~1400 hours and
with symptoms of a problem and intending to go offshore again it's
probably worth a few hundred to me to have the pump re-built. Another
source of smoke might be coking at the exhaust elbow. I'll pull them
and check that. The valve timing might well be out and that's easy to
check.

-- Tom.