I installed the Aqualarm raw water alarm last spring and there was
some discussion here. I had some calibration issues and finally
decided that it should be treated as a water flow stoppage alarm and
couldn’t be used to warn of diminished flow. The manufacturer
confirmed that this was the case, at least with a small engine
operating near the bottom of the calibration range.

There were some responses that "real" sailors checked the exhaust
water flow every two or three minutes and didn’t depend on gadgets. I
began to wonder myself is the unit was just one of those enthusiasms
you have when outfitting a new boat. (My very basic panel doesn’t have
water temp gauges or even room for them.)

I was hunkered down in the cockpit yesterday grimly motoring into 25
mph wind and chop on the way to get the boat hauled for the winter
when the beeping started. I checked the water pump and it was hot.
There is no way I could have seen the water flow under the counter in
those conditions. The Aqualarm certainly saved me from an overheat
event.

I finished the trip under sail. The strainer was clear, the impeller
looked good, I’ll have them figure it out when they winterize the
engine.

Full story he

http://home.maine.rr.com/rlma/Boat20.htm#Latest

--
Roger Long

Roger,
Could you have gotten an airlock in your raw water system if the conditions
were right to lift the engine intake out of the water? I had the problem
once in my fresh water side after working on the exchanger.
I'd get a temp gauge and make room if I had to, but that's just my opinion.
I visually check the flow when I start the engine, then when ever I want to
stretch my legs, otherwise I depend on the temp gauge. I feel if the system
is maintained I can rely on it; I don't stop my car every few minutes to
look at the engine.
As for the "hunkered down in the cockpit yesterday grimly motoring into 25
mph wind and chop", isn't it strange how we never have engine problems
when the weather is nice and we aren't trying to get some where, or avoid
that barge, pier, rock, boat, iceberg, or aircraft carrier?
MMC

"Roger Long" wrote in message
...
I installed the Aqualarm raw water alarm last spring and there was
some discussion here. I had some calibration issues and finally
decided that it should be treated as a water flow stoppage alarm and
couldn't be used to warn of diminished flow. The manufacturer
confirmed that this was the case, at least with a small engine
operating near the bottom of the calibration range.

There were some responses that "real" sailors checked the exhaust
water flow every two or three minutes and didn't depend on gadgets. I
began to wonder myself is the unit was just one of those enthusiasms
you have when outfitting a new boat. (My very basic panel doesn't have
water temp gauges or even room for them.)

I was hunkered down in the cockpit yesterday grimly motoring into 25
mph wind and chop on the way to get the boat hauled for the winter
when the beeping started. I checked the water pump and it was hot.
There is no way I could have seen the water flow under the counter in
those conditions. The Aqualarm certainly saved me from an overheat
event.

I finished the trip under sail. The strainer was clear, the impeller
looked good, I'll have them figure it out when they winterize the
engine.

Full story he

http://home.maine.rr.com/rlma/Boat20.htm#Latest

--
Roger Long

Depending on the fresh water temp gauge to warn you when raw water flow
has been interrupted is probably not the best course of action for a
fresh water cooled engine. By the time you have a fresh water
temperature problem, you will probably have ignited your exhaust hose...

bob

MMC wrote:
Roger,
Could you have gotten an airlock in your raw water system if the conditions
were right to lift the engine intake out of the water? I had the problem
once in my fresh water side after working on the exchanger.
I'd get a temp gauge and make room if I had to, but that's just my opinion.
I visually check the flow when I start the engine, then when ever I want to
stretch my legs, otherwise I depend on the temp gauge. I feel if the system
is maintained I can rely on it; I don't stop my car every few minutes to
look at the engine.
As for the "hunkered down in the cockpit yesterday grimly motoring into 25

mph wind and chop", isn't it strange how we never have engine problems

when the weather is nice and we aren't trying to get some where, or avoid
that barge, pier, rock, boat, iceberg, or aircraft carrier?
MMC

"Roger Long" wrote in message
...

I installed the Aqualarm raw water alarm last spring and there was
some discussion here. I had some calibration issues and finally
decided that it should be treated as a water flow stoppage alarm and
couldn't be used to warn of diminished flow. The manufacturer
confirmed that this was the case, at least with a small engine
operating near the bottom of the calibration range.

There were some responses that "real" sailors checked the exhaust
water flow every two or three minutes and didn't depend on gadgets. I
began to wonder myself is the unit was just one of those enthusiasms
you have when outfitting a new boat. (My very basic panel doesn't have
water temp gauges or even room for them.)

I was hunkered down in the cockpit yesterday grimly motoring into 25
mph wind and chop on the way to get the boat hauled for the winter
when the beeping started. I checked the water pump and it was hot.
There is no way I could have seen the water flow under the counter in
those conditions. The Aqualarm certainly saved me from an overheat
event.

I finished the trip under sail. The strainer was clear, the impeller
looked good, I'll have them figure it out when they winterize the
engine.

Full story he

http://home.maine.rr.com/rlma/Boat20.htm#Latest

--
Roger Long

I'm not saying the Aqualarm isn't a good idea, but a whole lot of boats have
covered a whole lot of water before this device became available, and I was
stating my opinion that a temp gauge is very important.
So what do you rely on, an Aqualarm type device, or do you spend your trip
on the rail with your eyeball glued to the exhaust?
When I had the airlock in my fresh water side as desribed below, the temp
gauge got to about 200f and I shut it down. I've had cooling problems with
diesels before and never had a hose ignite. Nor heard of it happening.
My method has worked for me for a lot of years, so I think I'll continue...

"RW Salnick" wrote in message
...
Depending on the fresh water temp gauge to warn you when raw water flow
has been interrupted is probably not the best course of action for a
fresh water cooled engine. By the time you have a fresh water
temperature problem, you will probably have ignited your exhaust hose...

bob

MMC wrote:
Roger,
Could you have gotten an airlock in your raw water system if the
conditions
were right to lift the engine intake out of the water? I had the problem
once in my fresh water side after working on the exchanger.
I'd get a temp gauge and make room if I had to, but that's just my
opinion.
I visually check the flow when I start the engine, then when ever I want
to
stretch my legs, otherwise I depend on the temp gauge. I feel if the
system
is maintained I can rely on it; I don't stop my car every few minutes to
look at the engine.
As for the "hunkered down in the cockpit yesterday grimly motoring into
25

mph wind and chop", isn't it strange how we never have engine problems

when the weather is nice and we aren't trying to get some where, or
avoid
that barge, pier, rock, boat, iceberg, or aircraft carrier?
MMC

"Roger Long" wrote in message
...

I installed the Aqualarm raw water alarm last spring and there was
some discussion here. I had some calibration issues and finally
decided that it should be treated as a water flow stoppage alarm and
couldn't be used to warn of diminished flow. The manufacturer
confirmed that this was the case, at least with a small engine
operating near the bottom of the calibration range.

There were some responses that "real" sailors checked the exhaust
water flow every two or three minutes and didn't depend on gadgets. I
began to wonder myself is the unit was just one of those enthusiasms
you have when outfitting a new boat. (My very basic panel doesn't have
water temp gauges or even room for them.)

I was hunkered down in the cockpit yesterday grimly motoring into 25
mph wind and chop on the way to get the boat hauled for the winter
when the beeping started. I checked the water pump and it was hot.
There is no way I could have seen the water flow under the counter in
those conditions. The Aqualarm certainly saved me from an overheat
event.

I finished the trip under sail. The strainer was clear, the impeller
looked good, I'll have them figure it out when they winterize the
engine.

Full story he

http://home.maine.rr.com/rlma/Boat20.htm#Latest

--
Roger Long

I've given this some thought and alternative methods exist, like a
sensor on the block keyed to alarm at 180 F. A sensor on the oil
pressure sensor that beeps if pressure drops below, say, 15 PSI, is
helpful, too.

I use a plastic basket-type strainer with a clear, screw on cover
AFTER the water pump but BEFORE the block. If I notice the temperature
rising, or exhaust output gone (the exhaust "note" is also a tip-off),
I can check the basket for chunks of weed, impeller or whatever and
most importantly, keep that sort of crap out of the block.

With such a strainer, you can deduce whether the problem is external
or internal, and have a shot at remedying it underway if you carry the
right spares.

I had a bag sucked over the raw water strainer once that gave me
grief. Luckily, I noticed the temps rising, shut off the engine and
about 10 seconds later, saw a misshapen plastic bad float aft.

Another minute of that would have fried my block, probably.

R.

On Thu, 13 Oct 2005 10:33:13 GMT, "Roger Long"
wrote:

I installed the Aqualarm raw water alarm last spring and there was
some discussion here. I had some calibration issues and finally
decided that it should be treated as a water flow stoppage alarm and
couldn’t be used to warn of diminished flow. The manufacturer
confirmed that this was the case, at least with a small engine
operating near the bottom of the calibration range.

There were some responses that "real" sailors checked the exhaust
water flow every two or three minutes and didn’t depend on gadgets. I
began to wonder myself is the unit was just one of those enthusiasms
you have when outfitting a new boat. (My very basic panel doesn’t have
water temp gauges or even room for them.)

I was hunkered down in the cockpit yesterday grimly motoring into 25
mph wind and chop on the way to get the boat hauled for the winter
when the beeping started. I checked the water pump and it was hot.
There is no way I could have seen the water flow under the counter in
those conditions. The Aqualarm certainly saved me from an overheat
event.

I finished the trip under sail. The strainer was clear, the impeller
looked good, I’ll have them figure it out when they winterize the
engine.

Full story he

http://home.maine.rr.com/rlma/Boat20.htm#Latest