Speedometer Paddle Wheel Stuck

[SirMichael]

I have a 1988 Hunter 28.5 And pretty much every year here lately, the paddle wheel for the speedometer has gotten stuck about halfway through the season. What, I’m not moving???

Does anyone have any ideas on how to get this rolling again? I am at an age where I’m not that crazy about diving down in the gunky water of the Marina to try to free it.

I have searched the forum but haven’t found any solutions that would work for this type of boat.

I have considered putting on a GPS type speedometer, but my concern is that I’m in Lake Pepin, which is a part of the Mississippi river, and there is water flow, so it wouldn’t be very accurate for me.

Suggestions?

Sir Michael

 

[kappykaplan]

You should get a blanking plug for the speed wheel through hull and remove the speed wheel/insert blanking plug when you're not using the boat.

 

[Ralph Johnstone]

I have no idea whatsoever as to what speed sensor you have even though our boats are somewhat related but separated by 10 years. That's why you always state a make and model number when talking about equipment. I'll take a wild, hairy guess and say that you likely did have a blanking plug (as per @kappykaplan ) attached by a SS ring to your sensor housing at some time. These sensors are notorious for fouling in salt water where a week without movement will allow growth on the paddles. I have given up on mine and rely only on the GPS in the ocean.

Find the make and model of the sensor, Google it, see if you can purchase the plug separately.

 

[SirMichael]

I did state the make and model, it's a 1988 Hunter 28.5. I have no idea what the make or model number is of the speedometer. All I know is that there is a small paddle wheel that drops out of the bottom of the boat that is supposed to turn and indicate the speed. It gets fouled about July or August.

No salt water, I'm in the Mississippi. GPS won't work well here with the current...

Sir Michael

 

[BlowMeAway]

I never considered a blanking plug, but after the 2nd year of ownership and finding my paddle wheel crushed by the travel lift strap (twice) and attempting to replace a no longer available thru hull sensor…I just installed a GPS system and used SOG as my speed. I did find a plug that fits the original through hull fitting.

 

[Calif. Ted]

I did state the make and model, it's a 1988 Hunter 28.5.

Not the boat, the knotmeter, Raymarine, B&G etc. you remove the paddlewheel from INSIDE the boat and replace with a blanking plug while you clean it. If you search you tube there are many videos describing how to clean.

 

[Ralph Johnstone]

I did state the make and model, it's a 1988 Hunter 28.5.

The 1998 Hunter 28.5 is a boat, not a car. A boat run of any model boat can and will have different equipment on it depending on availability and price. With Hunter it's all good equipment, it may just vary during the production run.

I have no idea what the make or model number is of the speedometer.

Then you sir, are SOL as that is the only way you'll be able to do a web search for that sensor and its blanking plug. What is the make and model of the speed gauge or readout ?

All I know is that there is a small paddle wheel that drops out of the bottom of the boat that is supposed to turn and indicate the speed.

I can only describe what I see on my 1999 H-310 which is a paddle housing that is removed from "inside" the hull. When it is pulled, two rubber flaps snap back over the hole and outside water dribbles in very slowly to allow you to insert the blanking plug with about a half cup of water to clean up after. To save a haul out, try pulling the paddle housing and placing a bathroom plunger over it to stop the slow leak. You should find the make and model of the sensor on the body. That is, unless your sensor is completely different than mine.

 

[jdrutten]

Zebra mussels. Of course you need the blanking plug as mentioned. But those little buggers can be insidious. I pulled mine a couple weeks ago because it was fouled for the same reason. The problem is that you need to be very thorough. Toothpicks, tooth brushes, dental floss (I guess it’s an oral theme), whatever you can can fit in there. If you miss one of those adorable baby mussels which had deposited itself inside the crevices of the wheel, it will continue growing and a week or two later it will foul the wheel again and you’ll be pulling and cleaning once more. If you don’t have the blank plug, I’d take Ralph’s advice and find some way to plug it temporarily while you take a minute or two to clean it. If you don’t mind a little water in the bilge you could probably just let your bilge pump take care of the water for a few minutes. But that might not be the most relaxing way to go.

 

[Don S/V ILLusion]

The make/model of the plug should be obvious by noting what it says on the speed display. That in turn will identify if there is a plug
The type boat it’s on is irrelevant.

 

[Hayden Watson]

Zebra mussels. Of course you need the blanking plug as mentioned. But those little buggers can be insidious. I pulled mine a couple weeks ago because it was fouled for the same reason. The problem is that you need to be very thorough. Toothpicks, tooth brushes, dental floss (I guess it’s an oral theme), whatever you can can fit in there. If you miss one of those adorable baby mussels which had deposited itself inside the crevices of the wheel, it will continue growing and a week or two later it will foul the wheel again and you’ll be pulling and cleaning once more. If you don’t have the blank plug, I’d take Ralph’s advice and find some way to plug it temporarily while you take a minute or two to clean it. If you don’t mind a little water in the bilge you could probably just let your bilge pump take care of the water for a few minutes. But that might not be the most relaxing way to go.

Leave the blanking plug in between uses and only put the impeller in when you go sailing.

 

[kappykaplan]

Leave the blanking plug in between uses and only put the impeller in when you go sailing.

 

[shemandr]

It took half a season to get fouled? I used to clean mine weekly.

 

[Ward H]

Boy, tough crowd,
@SirMichael, I don’t believe you are ”SOL” since practically all instrument manufacturers use Airmar transducers And Airmar didn’t make that many models of paddle wheel transducers in 88 if more than one and there probably is only one size tube and blank Plug.
Just go to https://www.airmar.com/. Look for a tech support number, call them and they can most likely give you the part number you need IF in fact you need a blanking plug because you most likely have one.
What you need to do is find the transducer inside your boat. You already know what area it’s most likely in from where you see it on the outside. Start looking in cabinets and cubby holes for a 2” diameter 6” long pipe sticking up from the hull with a wire sticking out of it. You probably have 2, one for depth and one for paddle wheel. When you find it look for the Blank Plug. It should be close by.
If you can’t find it then look for a tag on the wire with serial number. Don’t take the transducer out to look for a number on it. Then call Airmar about a blanking plug.

Then what Ted said.

. you remove the paddlewheel from INSIDE the boat and replace with a blanking plug while you clean it. If you search you tube there are many videos describing how to clean.

 

[shemandr]

I used to keep a small putty knife, a toothbrush and a cut off plastic container right at the paddlewheel site to help clean it and to contain the mess. Best practice is to only have the paddle wheel in while sailing and the blank in at all other times. But ...

 

[Gary Ryan]

I have the same problem this year on our Hunter 386. I dove under the boat and noted that the sensor had a stick in it and had spun about 45 degrees. Not sure if I got all the stick out. It reads 3 knots max. Navionics on my iPad has our speed, so we're good. I'll fix it when we pull it in a few months.

 

[Windpilot]

SOG from gps only and some of you guys are happy with just that. Just wow.

 

[Davidasailor26]

If you can get a blanking plug as others have suggested that would be best. I don’t know if that would still be possible for a 35 year old transducer.

If you don’t want to go all out diving to clear the wheel you could start with just a swim and a long handled scrub brush. I can reach mine and clean it up a little that way. If there’s hard growth like barnacles or mussels it won’t fix the problem, but if it just has some slime it might help.

 

[SirMichael]

Ward,

Thank you, I appreciate your help!

I wasn't aware of the possibility of using a blanking plug when the boat was in the water. That might be what I need to do. I will need to do some checking under the front V-berth to see if I can find where that tube comes up and see if that is possible to remove it while I'm in the water. I'm assuming that some water might get into the boat, but you just clean that up afterwards.

Again, thank you!

Sir Michael

 

[kappykaplan]

I'm assuming that some water might get into the boat, but you just clean that up afterwards.

Correct. It will be a little disconcerting at first, but with practice, only a couple of cups of water will come in.

 

[Davidasailor26]

That is, unless your sensor is completely different than mine.

Or the flappy bit has failed, which mine has done twice. In that case (or if the thru hull never had a flap), the water will come in much more quickly. Still manageable if you’re just swapping in the blanking plug in, but probably not if you want to just hold the transducer in your hand to inspect and clean it without the backing plug.