Heard via email that at least one reader was interested in how the
Yanmar with the hunting problem worked on our passage from Honolulu to
San Fran. The executive summary is that the problem is still there
and I don't know what it is.

The complete saga follows:

The passage was plagued by calms and so we put a lot of hours on the
engines (by far the most ever for a single passage). We generally run
the engines singly and vary the rpms between 24-26 hundred. In
theory, the prop can only absorb ~6hp at those turns and the engine is
near max torque and min specific fuel consumption. And it's enough
power to keep the boat moving ~5 knots in a true calm and up to
~7knots motor sailing. The motors are rated 12 horse continuous so
that also seems like a conservative load. Because we've got the two
of them we seldom run one for more half a day and get to top off the
oil and inspect the Racor on the cold motor before we start it up.
Yet, by the end of the passage both motors were smoking at 24 and I'd
reduced turns to around 22. Except for the slight suggestion of
unburnt fuel in the exhaust of the port motor towards the end of the
passage it ran fine as always.

The starboard engine is another story. I think the underlying problem
maintaining rpms when cold is still there but the motor has developed
a couple of new problems. First, it has now got an air leak in the
fuel system somewhere. I had to bleed the system at the injectors a
couple of times when the motor had sat for a few days (we did get some
sailing in). This is new, or at least new to the extent that
perceptible air is released when the injector is cracked. The motor
has also apparently developed leeks in the fuel system (well more
likely algae). We carry about half our fuel in cans and half in the
tanks. The tanks for both engines have pretty much always been fueled
from the same source at the same time. I always use biocide. But the
fuel in the port engine looks perfect and the Racor bowl is clean and
the starboard engine had a massive algae bloom. The bowl was filled
with dead bugs and I changed out the filter twice (R26S). It's a big
filter for such a small engine but it did get full of bugs. I don't
have a vacuum gage on it. So, the stb engine still needs to be
warmed up before it will hold it's rpms but it's also got these new
problems... And, it too is smoking at 24 and so I reduced it's turns
to 22 as well...

Anybody know a good Diesel mechanic in the Bay Area? Also, I
apparently need a tank polishing service...

-- Tom.

PS. I recently noticed that sailmail has some ability to send stuff
to a blog site. If there would be any interest I'd be willing to check
it out and maybe post some of our passage notes as blogs. Yes, no,
maybe?

-- T.

wrote in message
...
Heard via email that at least one reader was interested in how the
Yanmar with the hunting problem worked on our passage from Honolulu to
San Fran. The executive summary is that the problem is still there
and I don't know what it is.

The complete saga follows:

The passage was plagued by calms and so we put a lot of hours on the
engines (by far the most ever for a single passage). We generally run
the engines singly and vary the rpms between 24-26 hundred. In
theory, the prop can only absorb ~6hp at those turns and the engine is
near max torque and min specific fuel consumption. And it's enough
power to keep the boat moving ~5 knots in a true calm and up to
~7knots motor sailing. The motors are rated 12 horse continuous so
that also seems like a conservative load. Because we've got the two
of them we seldom run one for more half a day and get to top off the
oil and inspect the Racor on the cold motor before we start it up.
Yet, by the end of the passage both motors were smoking at 24 and I'd
reduced turns to around 22. Except for the slight suggestion of
unburnt fuel in the exhaust of the port motor towards the end of the
passage it ran fine as always.

The starboard engine is another story. I think the underlying problem
maintaining rpms when cold is still there but the motor has developed
a couple of new problems. First, it has now got an air leak in the
fuel system somewhere. I had to bleed the system at the injectors a
couple of times when the motor had sat for a few days (we did get some
sailing in). This is new, or at least new to the extent that
perceptible air is released when the injector is cracked. The motor
has also apparently developed leeks in the fuel system (well more
likely algae). We carry about half our fuel in cans and half in the
tanks. The tanks for both engines have pretty much always been fueled
from the same source at the same time. I always use biocide. But the
fuel in the port engine looks perfect and the Racor bowl is clean and
the starboard engine had a massive algae bloom. The bowl was filled
with dead bugs and I changed out the filter twice (R26S). It's a big
filter for such a small engine but it did get full of bugs. I don't
have a vacuum gage on it. So, the stb engine still needs to be
warmed up before it will hold it's rpms but it's also got these new
problems... And, it too is smoking at 24 and so I reduced it's turns
to 22 as well...

Anybody know a good Diesel mechanic in the Bay Area? Also, I
apparently need a tank polishing service...

-- Tom.

PS. I recently noticed that sailmail has some ability to send stuff
to a blog site. If there would be any interest I'd be willing to check
it out and maybe post some of our passage notes as blogs. Yes, no,
maybe?

-- T.


I have no trouble recommending KKMI. They're very well-respected as a boat
yard.

Yes! Blog away!

--
"j" ganz @@
www.sailnow.com

" wrote in news:0bc6b40d-b372-405a-
:

First, it has now got an air leak in the
fuel system somewhere. I had to bleed the system at the injectors a
couple of times when the motor had sat for a few days (we did get some
sailing in). This is new, or at least new to the extent that
perceptible air is released when the injector is cracked.

Have the oil analyzed to look for fuel in the oil. If there's fuel in
the oil, the injection pump cylinders are leaking back oil past the
pistons into the crankcase of the engine as the engine oil also lubes the
injection pump crankcase. The injectors are higher than the pump, so
when the oil slides past the worn cylinders, air gets sucked in at the
nozzle and ends up in the injectors and injector lines you're bleeding to
get it to crank.

If there's no fuel in the crankcase, the injection pump has one or more
leaky fuel valves allowing fuel to back up back down towards the fuel
tank. Test this the next time you're going to leave the boat sitting for
a long period. Simply shut off the fuel tank valves as soon as you shut
down the engine, leave it all just sit for a few weeks, then see if air
bleeds out instead of fuel as soon as you crank. If air is STILL in the
injector lines, it'll also point you to problem A above, backing up into
the crankcase from the leaky pistons in the injectors because it can't
back up to the tank with the fuel valves all closed off. Pinch off the
return line with vice grips at the hose if there's no valve.

Air leaks are very interesting to find and correct....(c; But, if these
are the problem, it's not a fuel line air leak making the problem. Air
leaks don't occur sitting for days....fuel backup does.

Maybe that's what these guys are looking for in the crankcase....fuel
backup!
http://gcaptain.com/maritime/blog/th...-super-engine/
Air leaks there would be measured in cu ft....not bubbles in the
filter...(c;

On May 27, 9:26 am, Larry wrote:
... Air leaks are very interesting to find and correct....(c; But, if these
are the problem, it's not a fuel line air leak making the problem. Air
leaks don't occur sitting for days....fuel backup does.
....

Sounds like all roads lead to the injector pump. It's probably a good
idea to have it rebuilt anyway while we're here in the land of
plenty. There must be shop around here somewhere that does injector
pumps. Thanks for the input.

-- Tom.

" wrote in
:

On May 27, 9:26 am, Larry wrote:
... Air leaks are very interesting to find and correct....(c; But, if
these
are the problem, it's not a fuel line air leak making the problem.
Air leaks don't occur sitting for days....fuel backup does.
...

Sounds like all roads lead to the injector pump. It's probably a good
idea to have it rebuilt anyway while we're here in the land of
plenty. There must be shop around here somewhere that does injector
pumps. Thanks for the input.

-- Tom.



Don't forget to take the injectors with you so they can be spray tested
while it's out....

On May 27, 10:14*pm, Larry wrote:
" wrote :

On May 27, 9:26 am, Larry wrote:
... Air leaks are very interesting to find and correct....(c; *But, if
these
are the problem, it's not a fuel line air leak making the problem.
Air leaks don't occur sitting for days....fuel backup does.
...

Sounds like all roads lead to the injector pump. *It's probably a good
idea to have it rebuilt anyway while we're here in the land of
plenty. *There must be shop around here somewhere that does injector
pumps. *Thanks for the input.

-- Tom.

Don't forget to take the injectors with you so they can be spray tested
while it's out....

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.

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.