Running the Honda's

[a64pilot]

Came off of a couple of weeks of cruising in really hot weather, as such I wanted to run my little Honda's in anchorages where I was by myself so we could AC the boat
I've got one of these at work and brought it with me Scott Mini-SA Carbon Monoxide (CO) :: Argus-HAZCO
Anyway no matter where on the boat I put the Gen's, even when there was a good breeze off of the bow, I would get CO in the cabin, always more than 10PPM, sometimes as high as 50PPM, near as I can tell 100PPM is the threshold where it becomes deadly. I never did smell the exhaust, I know CO is odorless, but the rest of the exhaust isn't. I had always assumed if I were getting CO in the boat I could smell a little bit of exhaust. I don't smoke and have a pretty good sense of smell I thought
The only place I could put them to get to 0 PPM of CO was in the dinghy with it lowered down near or in the water. Another plus was with them in the dinghy, you couldn't hear them in the boat with the boat closed up and the AC on.

Anyway CO poisoning is cumulative, so be careful with these things

[a64pilot]

Can you mods delete one of these duplicate posts?

[Bendecida]

Good advice, thanks for the reminder.

Also, with the genset down in the dinghy, be very careful about getting salt water on your unit or on the electrical connections. One dip in the brine and your copper connections and cord will begin to oxidize (rot), creating resistance to electrical flow and eventually heating up to a dangerous level. Then, of course, you have to spend a boat buck for new cables

Cheers,
BOB and BENDECIDA crew
Bequia, SVG

[Tripod]

I don't think the Scott Mini-SA uses a time-weighted average like marine-rated CO detectors. If it doesn't you'll get lots of false alarms. It's the buildup of CO that you have to worry about, not transient readings. Even an outboard motor passing upwind of you will trip most non-marine CO detectors.

[beneteau-500]

I have found this interesting in the fact that I ran a gas boiler repair business for 25 yrs and one of the things I always pushed onto the customers was to have Co2 detectors fitted , what I find interesting is the detector has only a 2 yr life which is low . now all the detectors I have fitted (1000s) have between 5 & 7 yr warranties on them . So first question how old is your detector , where was gen sited when running , where is detector sited or left laying around in yacht , is it left in sunlight if so after 400 milli cervets of radiation sunlight the sensors will degrade And trigger an alarm If you had gen on deck and detector in closed forward cabin does alarm go off ?

[leftbrainstuff]

That is why a wet exhaust that exits close to the waterline works so well on a boat.

A diesel generator is a much more practical and safer option. Uses less fuel too.

I'd be annoyed having to listen to a gasoline generator running all night in a dinghy with the exhaust note reverberating around the anchorage all night.

We've seen too many false positives from the cheap CO2 detectors. Maintaining good quality airflow down below is safer than trusting a detector that was only designed to work in a closed environment.

Sent from my GT-I9300 using Cruisers Sailing Forum mobile app

[a64pilot]

The CO detector I have is because I'm a test pilot and we build a new aircraft on average of one a week, One of the certification requirements is to ensure the cockpit is free of an CO during it's certification test flight.
It's I believe a lab quality instrument and is sent back to the manufacturer on a 90 day calibration cycle and is tested / calibrated to NIST standards. Before each use it's tested with "bump" gas which is nothing more than a small quantity of CO in a spray paint can, but the exact percentage of CO is known so you can test functionality and accuracy

I am absolutely sure it's readings were correct, I'm sure also that it is not a time weighted average, it's reads what it detects at that instant, no averaging.

Only think I am trying to warn people is that I was getting significant level of CO in the boat with the boat sealed up, the gen sets in the back of the cockpit and 3 or 4 kts of wind off the bow, and had no exhaust smell at all.

Just be careful if you use a portable generator, I went out and got a CO detector from Lowe's, but it is a time weighted thing, that is it takes a high level to set the thing off, but lower levels for longer periods will set it off, it also has an "end of life alarm" I don't have a clue how or why, but apparently these things have a limited life span and even the cheap ones at Lowe's can monitor that and will alert you when it's time to replace it.
If you run a portable genset, get a detector, you really can't smell the exhaust.

[Tellie]

Exhaust fumes are a tricky thing to consider when designing a boat. Even with the wind coming straight from the bow to aft, convection's created by the boats shape and additions can bring fumes right back into the boat especially at anchor this can be more pronounced. Gentle breezes seem to cause this effect even more. Raising the exhaust from any engine, as would be done by a portable generator is a bad idea. I was guilty of this as well when I used to use a small AC unit on those warm nights. My CO sensor at times would go off as well. I thought having it out on the sugar scoop would be enough ventilation. With a stiff wind there was no problem. It was the gentle to no wind that would back draft the CO into the boat. Being odorless and colorless it was a bit hard to see what was happening. When putting away my kids Halloween decorations a few years ago I came across one of those fog machines. Had the crazy idea of taking it to the boat to try an experiment with it. Set the thing up in several spots where I would consider running the generator and sure enough in a gentle breeze the visible fog would back draft into the boat. Not very scientific to be sure but it demonstrated the effect quite well.

[Canibul]

How about rigging a wind scoop over the honda?

hey A64, you work for Thrush?

[onestepcsy37]

We were moored in vero beach next to a hunter with a "modern" transom. At night he ran TWO honda 2000's, for his a/c I guess, sitting on his swim platform. Though just 50 feet from them, we couldn't hear them running.

Sent from my GT-P3113 using Cruisers Sailing Forum mobile app

[a64pilot]

Originally Posted by Canibul

How about rigging a wind scoop over the honda?

hey A64, you work for Thrush?

Yes..

[a64pilot]

Originally Posted by Tellie

Exhaust fumes are a tricky thing to consider when designing a boat. Even with the wind coming straight from the bow to aft, convection's created by the boats shape and additions can bring fumes right back into the boat especially at anchor this can be more pronounced. Gentle breezes seem to cause this effect even more. Raising the exhaust from any engine, as would be done by a portable generator is a bad idea. I was guilty of this as well when I used to use a small AC unit on those warm nights. My CO sensor at times would go off as well. I thought having it out on the sugar scoop would be enough ventilation. With a stiff wind there was no problem. It was the gentle to no wind that would back draft the CO into the boat. Being odorless and colorless it was a bit hard to see what was happening. When putting away my kids Halloween decorations a few years ago I came across one of those fog machines. Had the crazy idea of taking it to the boat to try an experiment with it. Set the thing up in several spots where I would consider running the generator and sure enough in a gentle breeze the visible fog would back draft into the boat. Not very scientific to be sure but it demonstrated the effect quite well.

Actually pretty scientific, using the smoke machine
being a Jim Bob myself, we all have peek up trucks, with your peek up you can see a little bit of trash blowing around in a circle in the bed, I had assumed that is what was going on with the fumes in the boat, and of course what you describe with the smoke machine

[a64pilot]

Originally Posted by onestepcsy37

We were moored in vero beach next to a hunter with a "modern" transom. At night he ran TWO honda 2000's, for his a/c I guess, sitting on his swim platform. Though just 50 feet from them, we couldn't hear them running.

Sent from my GT-P3113 using Cruisers Sailing Forum mobile app

Two of them in Eco mode isn't nearly as loud as one running hard, my two will start my 16K AC, charge batteries and run TV's etc in Eco mode.
I want one of those inverter / chargers that will absorb start up loads
Where I usually anchor, it's not hard to find an anchorage all to yourself, I never have and will not pull into an anchorage where there are other boats and start my Gens, but If I'm at anchor with them running and you pull up near me I won't shut them down either.
I've only run them twice, usually can get by without them, last time I ran them we were anchored out by Dog Island and the Horse flies were carrying us off and we had to close up the boat.

[JPA Cate]

A64pilot,

We've seen a number of gensets used on the boat's stern. Am I understanding you correctly that you think that is unsafe? Thanks for the answer.

Ann

[Vasco]

I've seen folks attach a hose to the Honda's exhaust and direct it down over the side close to the waterline. Even with a ten knot breeze fumes from a Honda on the swim platform will come back into the cockpit and into the boat. It's like driving a station wagon (they still make those?) with the rear window down. I find a better position for the Honda is on a side deck with the exhaust angled out.