Hi, I'm a new sailboat owner and my speedometer is not working. It worked the first few weeks and now it's not. The DC electric is on and the other instruments are working, but not the speedo. Is it ok to remove the through-hull unit to check to see if it is clean? I have the temporary plug but the boat is in the water and I don't want to remove the unit and not be able to get the plug in. Any advice?
No Speedometer Reading
- Thread starter bnort3
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knotmeter probably fouled
Your knotmeter is probably fouled with marine growth (algae and such). sometimes it gets swept off while sailing and suddenly, it will start spinning again. If not, have a plug handy,( it helps to have 2 people) because the water comes in fast! Remove the knotmeter, shove the plug in, clean and then replace. You should not get more than a gallon if you switch them quickly. Good luck... it's scary the first time! Steph
Your knotmeter is probably fouled with marine growth (algae and such). sometimes it gets swept off while sailing and suddenly, it will start spinning again. If not, have a plug handy,( it helps to have 2 people) because the water comes in fast! Remove the knotmeter, shove the plug in, clean and then replace. You should not get more than a gallon if you switch them quickly. Good luck... it's scary the first time! Steph
Re: knotmeter probably fouled
Thanks, Steph. That's what I was afraid of. It is a little scary. Wonder if I should just go for a little swim underneath the boat and try to clean it out?
Thanks, Steph. That's what I was afraid of. It is a little scary. Wonder if I should just go for a little swim underneath the boat and try to clean it out?
Not only OK but essential. I have to pull and clean mine about every two weeks even in Maine where there isn't a lot of fouling.
Be quick. Be smooth. Think through your moves. Don't drop the plug
There will be a huge spurt of water that makes a big mess. It helps to drape a garbage bag or something similar over the area. Lubricate the plug and transducer well with something that is plastic friendly like Teflon grease which you can get at a bicycle shop.
I've taken mine out a few times ( Raymarine ) typically before and after haul out so it doesn't get caught in the straps. Water does come in, but not enough to really be worried about. Have the plug handy, familierize yourself with its orientation, pull the knotmeter and put in the plug. Don't panic and take your time, otherwise it'll take twice as long. I get very little water in and can be mopped up with a cloth.
bnort3, you might as well get use to doing the dummy-plug mambo. I'm down in Back Creek/Annapolis, and I'd say if the boat is not used in two weeks, the knotmeter paddlewheel gets clogged. SOMETIMES it will unclog when the boat moves. My B323 thru-hull is in a cubby under the vee berth, and two people cannot get in. I think it is better with just one person anyway. A hand on the sender, a hand on the dummy. I always put a bath towel around the area to keep water from running more than a few inches. I've gotten to where there is less than a quart of water coming in when doing the change. Perhaps you'll just leave the dummy plug in place until you need the knotmeter function. I do not need the knotmeter on daysails since I have the chartplotter with GPS, but when I do more than a daysail I like the ship's log to be counting the miles.
I assume you have a locking ring on the top of the sender? Unscrew it until it's undone, but make sure the sender does not pop out yet- it likely will not. You will probably have to turn the sender a little bit back and forth to break it loose. Continue the back and forth motion as you back it up. When the little bit of water trickles in, you know it's almost free to pull out. You need to have the plug in one hand, and I'd say use the hand that your are. Right-handed? The coordination to put the dummy in place is important. Like the guy who does the "pea-under-the-cup-game", pull out the sender and push in the dummy. Both units have a key molded into the housing, so be sure to keep the "front" arrow pointing forward. Maybe even paint it whilte for easier location. You might have to move the dummy to and fro to get the key into place, but keep the arrow frontward. Tighten down the locking ring. I put Vaseline on the rubber rings to help it slide in and out. IF there is enough slack in the wiring, you could put a hand over the thru-hull while someone else cleans the paddlewheel with a toothbrush or grout-cleaning brush. You might have to push out the axle pin to take out the paddlewheel to give it a good cleaning. When clean, spin the paddle and make sure the display gets a reading! Yes, you MIGHT be able to clean it in the water, but you'd need a long-bristle brush.
I was on a charter boat that the knotmeter did not work. I knew what the problem was, and cleaned the paddlewheel while we were on the move. It seemed there was less water coming in when the boat was moving.
I assume you have a locking ring on the top of the sender? Unscrew it until it's undone, but make sure the sender does not pop out yet- it likely will not. You will probably have to turn the sender a little bit back and forth to break it loose. Continue the back and forth motion as you back it up. When the little bit of water trickles in, you know it's almost free to pull out. You need to have the plug in one hand, and I'd say use the hand that your are. Right-handed? The coordination to put the dummy in place is important. Like the guy who does the "pea-under-the-cup-game", pull out the sender and push in the dummy. Both units have a key molded into the housing, so be sure to keep the "front" arrow pointing forward. Maybe even paint it whilte for easier location. You might have to move the dummy to and fro to get the key into place, but keep the arrow frontward. Tighten down the locking ring. I put Vaseline on the rubber rings to help it slide in and out. IF there is enough slack in the wiring, you could put a hand over the thru-hull while someone else cleans the paddlewheel with a toothbrush or grout-cleaning brush. You might have to push out the axle pin to take out the paddlewheel to give it a good cleaning. When clean, spin the paddle and make sure the display gets a reading! Yes, you MIGHT be able to clean it in the water, but you'd need a long-bristle brush.
I was on a charter boat that the knotmeter did not work. I knew what the problem was, and cleaned the paddlewheel while we were on the move. It seemed there was less water coming in when the boat was moving.
I'm at Severn House, across the creek and to your left (upstream) from those taller Watergate apartments.
Actually it is good to have two people. One to pull the transducer, the other person can just put a towel over the thru hull while the "puller" cleans off the paddle wheel. It is good to have a brush available to clean it off.
It only takes a few minutes to complete this process.
It only takes a few minutes to complete this process.
I always pull out my knot meter when I am back from sailing and install the dummy. Yes you must lubricate the rubber rings with Vasoline that contains Pertolium Jelly. This will not destroy the rubber and it will make it so that water does not leak inside. By removing the wheel it will never clog up.
I am not sure that Vaseline (petroleum jelly) is the best lubricant for orings. There are posts all over the internet about NOT using it on orings. I believe it makes a difference on what the orings are made from.
I would suggest a silicone grease like Super Lube if you are in doubt. It is a great product for your head pump too.
I would suggest a silicone grease like Super Lube if you are in doubt. It is a great product for your head pump too.
Most o-rings will be damaged by petroleum based products, including vaseline. Using a silicone-based o-ring specific grease is usually a good idea. Also, coating the paddlewheel with Desitin (anti-diaper rash ointment) will help reduce fouling issues.
It is indeed unsettling the first few times you do it, but it's something you get used to after a while. My husband used to pull the transducer, unfoul it, and replace it when we had no dummy plug -- talk about unsettling!
But seriously, if that is all it is, consider yourself lucky. Our boat eats instruments for lunch. We haven't had a functioning speedo or depth sounder for years. We go by a handheld Garmin GPS chart plotter.
But seriously, if that is all it is, consider yourself lucky. Our boat eats instruments for lunch. We haven't had a functioning speedo or depth sounder for years. We go by a handheld Garmin GPS chart plotter.
bnort -
I usually find when cleaning critters from the paddle wheel that just withdrawing the transducer halfway and plunging it up-and-down a couple of times in the modest stream of water that comes in around it is sufficient to remove the wildlife.
The amount of sea water that gets in is a lot less intimidating.
(With heavy seaweed around the wheel, I do have to remove it entirely and swap-in the plug. However, most other things, like nests of those ant-sized black shrimp-like critters are easily removed by the plunger method.)
Fair winds,
Al
s/v Persephone
I usually find when cleaning critters from the paddle wheel that just withdrawing the transducer halfway and plunging it up-and-down a couple of times in the modest stream of water that comes in around it is sufficient to remove the wildlife.
The amount of sea water that gets in is a lot less intimidating.
(With heavy seaweed around the wheel, I do have to remove it entirely and swap-in the plug. However, most other things, like nests of those ant-sized black shrimp-like critters are easily removed by the plunger method.)
Fair winds,
Al
s/v Persephone
Thanks
Ok, I now am confident that I need to clean it from the inside. Thank you all for your inputs. I love this forum and will be asking all kinds of questions so please bear with me.
Thanks again!
Happy Sailing,
Bob
Ok, I now am confident that I need to clean it from the inside. Thank you all for your inputs. I love this forum and will be asking all kinds of questions so please bear with me.
Thanks again!
Happy Sailing,
Bob
When the water comes in, you can probably see the small water-critters. They are not the biggest problem in the paddlewheel- it is the algea growth in the bay area. THAT usually will not just wash away. When the boat moves, enough algae might be knocked off so the wheel spins, but it's an indication that you will get additional growth before the next time you go out and the wheel won't rotate then.
It's all a fact of life on the Chesapeake Bay.
It's all a fact of life on the Chesapeake Bay.
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