Boat Problem Question
 

We are back home because we have an intermittent problem and decided
to come back to deal with it rather than wait and be stuck somewhere.

What is the problem?

Bob has his idea, but I'd like any alternate opinions.

We were motor sailing along, as the breeze basically died (although it
was from the predicted direction), and I was in the aft cabin when
suddenly it sounded to me as if the engine was running away. I went
up into the cockpit and said to Bob "What is that noise", and he said
there was someone coming up behind us. (We can't see directly behind
us due to stuff on the aft deck.) But I looked and there was no one
there. Bob slacked off the throttle and then cautiously came back to
speed and the noise was gone.

This happened about twice more. The gauges never moved during this
time - RPMs were the same, oil pressure normal, engine temperature
normal (and Bob checked that with the infrared gauge), engine charging
as normal. Bob checked the bilges and looked in the engine
compartment and saw nothing amiss. The engine continued to run as
normal between times.

We got to Crisfield just after 7 and tied up and went to dinner at the
Cove (wonderful dinner) and then we had a thunderstorm.

So yesterday, we were planning to go down to Cape Charles and decided
that was too far under the circumstances and were going to divert to
Deltaville. This happened once more, so we came home instead.

So what do you think this is?

Boat Problem Question
 

On Fri, 20 Jun 2008 08:49:34 -0400, Rosalie B.
wrote:

We are back home because we have an intermittent problem and decided
to come back to deal with it rather than wait and be stuck somewhere.

What is the problem?

Bob has his idea, but I'd like any alternate opinions.

We were motor sailing along, as the breeze basically died (although it
was from the predicted direction), and I was in the aft cabin when
suddenly it sounded to me as if the engine was running away. I went
up into the cockpit and said to Bob "What is that noise", and he said
there was someone coming up behind us. (We can't see directly behind
us due to stuff on the aft deck.) But I looked and there was no one
there. Bob slacked off the throttle and then cautiously came back to
speed and the noise was gone.

This happened about twice more. The gauges never moved during this
time - RPMs were the same, oil pressure normal, engine temperature
normal (and Bob checked that with the infrared gauge), engine charging
as normal. Bob checked the bilges and looked in the engine
compartment and saw nothing amiss. The engine continued to run as
normal between times.

We got to Crisfield just after 7 and tied up and went to dinner at the
Cove (wonderful dinner) and then we had a thunderstorm.

So yesterday, we were planning to go down to Cape Charles and decided
that was too far under the circumstances and were going to divert to
Deltaville. This happened once more, so we came home instead.

So what do you think this is?

Too bad you didn't record the sound. Since you said the gauges all
read no change in engine operation (boat speed didn't change?)
what could account for the sound?
I don't know boat drive trains, but have run across something similar
in a car. Traveling on the highway, there were occasional times when
something close to an "engine racing" sound would occur. Speed and
normal engine operation said otherwise, and the sound emanated from
the right side of the engine compartment. It was very obvious and
accompanied by some vibration. I suspected the CV joint.
I was wrong. Soon after the noise started occurring, the alternator
failed, and when it was replaced the noise was gone permanently.
Hopefully, it's something so minor for you.
You really have to pinpoint the source of the sound.
Again assuming engine operation remains steady, the exhaust system is
another place to look at.

--Vic

Boat Problem Question
 

Rosalie B. wrote:
....
We were motor sailing along, as the breeze basically died (although it
was from the predicted direction), and I was in the aft cabin when
suddenly it sounded to me as if the engine was running away.
....


Was it an exhaust type sound, which could be an exhaust leak or header
problem, or a mechanical sound, like a water pump or even alternator
bearing? Was there a vibration with it? As the Car Talk guys would
say, "Can you make the sound for us?"

Boat Problem Question
 

We had something very similar happen to us. Our PSS shaft seal makes
a gawd-awful noise when it get's a little air trapped in the shaft
log. It took me a while to track down the noise, but it went away
when we throttled back a bit until we could determine the source. If
you have a PSS shaft seal try burping it.

Boat Problem Question
 

"Rosalie B." wrote in message
...
We are back home because we have an intermittent problem and decided
to come back to deal with it rather than wait and be stuck somewhere.

What is the problem?

Bob has his idea, but I'd like any alternate opinions.

We were motor sailing along, as the breeze basically died (although it
was from the predicted direction), and I was in the aft cabin when
suddenly it sounded to me as if the engine was running away. I went
up into the cockpit and said to Bob "What is that noise", and he said
there was someone coming up behind us. (We can't see directly behind
us due to stuff on the aft deck.) But I looked and there was no one
there. Bob slacked off the throttle and then cautiously came back to
speed and the noise was gone.

This happened about twice more. The gauges never moved during this
time - RPMs were the same, oil pressure normal, engine temperature
normal (and Bob checked that with the infrared gauge), engine charging
as normal. Bob checked the bilges and looked in the engine
compartment and saw nothing amiss. The engine continued to run as
normal between times.

We got to Crisfield just after 7 and tied up and went to dinner at the
Cove (wonderful dinner) and then we had a thunderstorm.

So yesterday, we were planning to go down to Cape Charles and decided
that was too far under the circumstances and were going to divert to
Deltaville. This happened once more, so we came home instead.

So what do you think this is?



Helicopter or airplane most likely.

Wilbur Hubbard

Boat Problem Question
 

"Helicopter or airplane most likely."

That is so stupid it's actually funny!
right Wilbur/Gregory/???, they're being tracked by black, attack
helicopters.
They're being targeted for extermination.
As I have friends in high places, I've taken them off the hit list and
replaced their names with yours!!

Boat Problem Question
 

Wilbur Hubbard wrote:
"Rosalie B." wrote in message
...
We are back home because we have an intermittent problem and decided
to come back to deal with it rather than wait and be stuck somewhere.

What is the problem?

Bob has his idea, but I'd like any alternate opinions.

We were motor sailing along, as the breeze basically died (although it
was from the predicted direction), and I was in the aft cabin when
suddenly it sounded to me as if the engine was running away. I went
up into the cockpit and said to Bob "What is that noise", and he said
there was someone coming up behind us. (We can't see directly behind
us due to stuff on the aft deck.) But I looked and there was no one
there. Bob slacked off the throttle and then cautiously came back to
speed and the noise was gone.

This happened about twice more. The gauges never moved during this
time - RPMs were the same, oil pressure normal, engine temperature
normal (and Bob checked that with the infrared gauge), engine charging
as normal. Bob checked the bilges and looked in the engine
compartment and saw nothing amiss. The engine continued to run as
normal between times.

We got to Crisfield just after 7 and tied up and went to dinner at the
Cove (wonderful dinner) and then we had a thunderstorm.

So yesterday, we were planning to go down to Cape Charles and decided
that was too far under the circumstances and were going to divert to
Deltaville. This happened once more, so we came home instead.

So what do you think this is?



Helicopter or airplane most likely.

Wilbur Hubbard


I don't know what type of boat you have, but I have notice the some
frequencies resonate in my hull, when some motor boats come near. You
hear the boat in the distance but you also hear the boat noise
resonating in the hull. What you described could be the sound resonating.

Boat Problem Question
 

jeff wrote:

Rosalie B. wrote:
...
We were motor sailing along, as the breeze basically died (although it
was from the predicted direction), and I was in the aft cabin when
suddenly it sounded to me as if the engine was running away.
...

Was it an exhaust type sound, which could be an exhaust leak or header
problem, or a mechanical sound, like a water pump or even alternator
bearing? Was there a vibration with it? As the Car Talk guys would
say, "Can you make the sound for us?"

I thought it sounded like a racing engine as if the transmission had
gone wild. Yes there was vibration.

Bob (after he got over the idea that it was a big boat following us)
said it was a lot of vibration which you could hear better in the aft
cabin. He thinks it is the cutlass bearing that is shot, which will
require that we haul the boat to check and if that is it to replace
it. He will have to take off the prop which will be a pain as it is a
MaxProp

Boat Problem Question
 

Keith nuttle wrote:

Wilbur Hubbard wrote:
"Rosalie B." wrote in message
...
We are back home because we have an intermittent problem and decided
to come back to deal with it rather than wait and be stuck somewhere.

What is the problem?

Bob has his idea, but I'd like any alternate opinions.

We were motor sailing along, as the breeze basically died (although it
was from the predicted direction), and I was in the aft cabin when
suddenly it sounded to me as if the engine was running away. I went
up into the cockpit and said to Bob "What is that noise", and he said
there was someone coming up behind us. (We can't see directly behind
us due to stuff on the aft deck.) But I looked and there was no one
there. Bob slacked off the throttle and then cautiously came back to
speed and the noise was gone.

This happened about twice more. The gauges never moved during this
time - RPMs were the same, oil pressure normal, engine temperature
normal (and Bob checked that with the infrared gauge), engine charging
as normal. Bob checked the bilges and looked in the engine
compartment and saw nothing amiss. The engine continued to run as
normal between times.

We got to Crisfield just after 7 and tied up and went to dinner at the
Cove (wonderful dinner) and then we had a thunderstorm.

So yesterday, we were planning to go down to Cape Charles and decided
that was too far under the circumstances and were going to divert to
Deltaville. This happened once more, so we came home instead.

So what do you think this is?



Helicopter or airplane most likely.

Wilbur Hubbard


I don't know what type of boat you have, but I have notice the some
frequencies resonate in my hull, when some motor boats come near. You
hear the boat in the distance but you also hear the boat noise
resonating in the hull. What you described could be the sound resonating.

There were no airplanes or helicopters. We were looking because there
were (off in the distance) some menhaden boats and they sometimes have
a spotter plane, but I guess fuel is too expensive now. And we were
also looking because of being near some of the targets. But no
planes. And no other boats nearby. Bob at first thought we might
have picked up a crab pot, but there weren't any of those around
either.

Boat Problem Question
 

Rosalie B. wrote in
:

So what do you think this is?



As it's "behind the boat", I'd like to closely check the cutlass bearing.
They can make some horrible noises if something gets inside them or they
are wearing out. Their sounds radiate through the hull up the back of the
boat and I've heard their chatter sound like someone coming up behind the
boat before.

Worth having the diver take a look. Your hull needs scrubbing anyways I
can see from way over here....(c;