Posted by Bob Frew (rfrew@…>)
Dear Mark,
It is so good to hear from you, I hope that all is
well with you. Although I have a great boat I do not
get to use it very much and when I did on the worst
weekend of the year I got into trouble.
the boat was lifted at Brewer mystic to inspect the
prop, all was well.
Then the mechanic got it to behave like I did. The
problem was the fuel. I had left it alone too long and
an algae had formed and gumed up the filter. So he
cleaned it and added a mixture to the fuel.
He, Paul, was able to get it up to 3100rpm on sea
trial so I called Maxprop and they have suggested that
we reduce the setting by one which we will do when it
is hauled.
I am hopeful that we will get out to Block today, we
have not seen the Paynes all year.
Again all my best and thanks for such a complete
response to my email.
Regards, Bob Frew Freespirit, F32 Mystic
— Mark Edwards <markedwards55@…> wrote:
Hi Bob, I am not a mechanic but in my years of
customer service work
at Freedom I dealt with lots of similar issues. I
am not sure you
don’t have two things going on simultaneously. I
say that because
the fact that the engine alarms sounded is an
indicator of engine
overheating or low oil pressure. You said you felt
the engine and
it was not hot to the touch and the oil was OK so
perhaps you have a
faulty alarm. In any case it’s unlikely either low
oil or
overheating would by itself shut the engine down and
prevent it from
working later.
The engine shutting down is most likely fuel supply
related and most
probably air in the system introduced either in a
loose fitting or
from motor sailing without a full tank and thereby
allowing air to
be introduced at the pickup tube. The engine will
run a long time
on residual fuel in the lines before the air picked
up will get to
the injectors so you could have picked up air much
earlier than the
actual shut down would indicate. All Freedom owners
should know
that the fuel tanks should be kept full as possible
because the fuel
can wash to one side away from the pickup tube when
the tank gets
low and air will get in line but if the tanks are
topped up or at
least kept above 1/2 full then this can’t happen.
A second culprit can be a droop in the fuel tank
vent line that has
been filled with fuel and thereby is preventing air
from getting to
the tank to equalize pressure resulting in a vacuum
that will starve
the engine of fuel. The may explain why you could
run at low rpm’s
but not at higher rpms. To check this easily by
yourself, twist off
the fuel tank filler cap on deck and listen
carefully. If you hear
air being sucked into the tank the vent is a
problem. Run the
engine at high rpms with the cap off briefly to
prove or disprove
the theory.
A third fuel supply issue is the fuel tank pickup
tube itself may
have a fine mesh screen in the bottom that is not
supposed to be
there. I’ve seen this often get clogged with debris
from the tank
enough so the engine would not run at high rpms and
stall if you
tried to run her up. Check this by removing the
pickup tube from
the tank and inspect it. If you find the screen I
mentioned, remove
it and reinstall the tube in the tank. As a trial
get a can a clean
diesel and run the engine off that before
reinstalling the pickup
tube in the tank.
Another thought is the exhaust manifold. I have
seen so plugged by
carbon that you could not even stick a pencil in the
exhaust hole.
This causes a lot of back pressure on the exhaust
and can keep an
engine from running up to full rpms and this can
cause an engine to
stall. Exhaust manifolds need to be changed more
frequently than
they are.
In any case, even if your Max prop is not installed
with the correct
pitch setting, I believe that will not prove to be
the root cause of
the problem. Others have said correctly that an
over-pitched prop
will cause you to smoke and will deprive you of
proper running rpms
but by itself should not cause alarms to sound or
the engine to shut
down.
Good luck on this.
Mark Edwards
Pearson Composites (formally Freedom Yachts)
– In freedomyachts2003@yahoogroups.com, Bob Frew
<rfrew@…> wrote:
Thank you for all your responses. I should explain
further. The alarm did go off and the two red
indicators on the right illuminated. I checked the
engine. It was not steaming. the oil was normal
and
the water I was able to open and was normal. I did
restart the engine after 15 min and it started ok
I
kept it at 1500 rpm for 5 min and it seemed normal
I
made the mistake of increasing it to 1800 and it
stopped again so I called BoatUS. We have
unlimited
towing so we got back to port It cast Boat US
$480.
Now I face yard bills. I think the prop is the
first
to check.
thanks, Bob, Free spirit, Mystic F32