st40 bidata speed transduce cleaning?

[bcollis]

I don't have a manual, and I've looked over the ratheon website. I can't seem to find any docs on how to clean this thing short of getting in the water. I've pulled the rings off, but the top part does not seem to want to unscrew. What am I missing?

Thanks,

Brian

 

[Joe]

I don't have a manual, and I've looked over the ratheon website.
View attachment 48018

Uh... Brian.... I googled. "raymarine ST40 manuals" for you..... http://www.raymarine.com/Default.aspx?site=1&section=3&page=328

 

[Ron20324]

I assume it's in the water? If it's like my old boat, it does not unscrew, just pushes in & pull out, thus that captive pin. It has probably seized up from not being 'exercised' often enough. It looks like you'd have to pull the pin out and take that ring off the top and use a full-contact wrench- like an adjustable- to try to budge the thing left and/or right to break it loose. MAYBE you can stick a tool in the pin hole and pry it up a bit, but I'd try the adj wrench first.

Also, it could be held in by bottom paint.

 

[Joe]

If you removel the transducer ..... better make sure you have a plug to keep the water out... one should have come with the unit.... If not...... voila... the reason it hasn't been cleaned for a while.

 

[Manureva]

do not twist it side to side, if i remember corectly there are tab to keep the unit pointed the rigth way....just unscrew and pullout

 

[bcollis]

Sorry about the Google fail, Joe. I was using different search terms from my phone. I did see those manuals, but have yet to find the part that mentions how to get that plug out. The maintenance sections on speed don't seem to cover that.

The boat is out of the water, but since the speed wheel gets fouled quickly, I want to know how to clean it while in the water. I didn't want to experiment before I hauled out for the obvious reasons.

I pulled the bottom pin out last week and heard something fall down inside. Everything on the underside looked normal, so I'm not sure what I heard fall.

I think I may have some plugs in the boat... I wasn't sure before what they went to.

So I need to get the bottom pin out, and simply twist or pull the black top out? It does not unscrew?

 

[Ron20324]

do not twist it side to side, if i remember corectly there are tab to keep the unit pointed the rigth way....just unscrew and pullout

If you can't twist it, then you can't unscrew it

 

[Ron20324]

... but since the speed wheel gets fouled quickly]...

Here in Annapolis if I leave the paddle wheel in the water for 2 weeks I have to clean it to free the wheel. So, i'f i'm not using within the next week, I pull it out and put in the dummy plug.

I pulled the bottom pin out last week and heard something fall down inside.

Was this working before?

So I need to get the bottom pin out, and simply twist or pull the black top out? It does not unscrew?

Unless someone or the manual says otherwise for sure, I'd say yes, just pull. Or maybe you can push from the outside?

 

[RichH]

The bidata transducer does not TWIST-OUT ... it comes 'straight out' and without twisting. There is a clam shell valve in built-in to the thru-hull ... to minimize back-flow into the boat when the transducer is removed, although you need to insert the 'dummy plug' to prevent flooding/leakage when cleaning the transducer as the 'clam shell valve' isnt 'perfect'.
Unscrew the large 'bezel cap' ring, grab ahold of the large 'wire ring' and pull 'straight up', and quickly insert the 'dummy plug', etc.

When reinserting the transducer note that there is an arrow embossed/raised on the area where the large metal ring attaches, the arrow faces toward forward. When inserting there is 'detent' (lug) in the rim of the transducer that matches with the thru-hull ... twist the transducer until the 'detent' lines up and push all the way in, then screw down the 'cap'.

Use ONLY water based transducer bottom paint on the transducer and its thru-hull ... solvent based bottom paints are incompatible with these transducers/thruhulls --- the soften and SWELL in contact with solvent based bottom paint.

 

[joker460]

From your photograph the wire going into the housing threw me off. It's not like any of the newer airmar transducers.

I did see a Patent from airmar 1988 and have attached the drawing. It looks similar to yours but you may not have the temp and depth part.

Good Luck

 

[bcollis]

Went to the boat after work and managed to get the plug out. I had to use vise grips... It was very tough, and I doubt it has ever been pulled out. The PO said that he cleaned it by getting in the water.

There was no flange or anything other to restrict water with the plug removed. I am curious how much of gyser I would have if I were to pull it while in the water. I'm not sure if I would try it.

Thanks for everyone's help. Without the info I'm pretty sure I would have destroyed it, or taken the safer route and left it alone.

Thanks again,

Brian

 

[bcollis]

Picture of the removed plug

 

[Ron20324]

Those are probably rubber O rings. It's a good excuse to have KY on the boat- to lube the rings. If it's been in all this time, maybe get new rings while you're cleaning it up?

 

[Joe]

I have an old Horizon series 1 (produced in UK before Raymarine took over) I came with a dummy plug, it looks just like the transducer..... anyhow, when you pull the transducer to clean it, you must quickly insert the dummy plug.... water will still come during the transition...but if you're quick you limit it to a quart or so.... What's impressive is how fast the water flows....

I don't remove the transducer as much as I used to.... in fact, I now leave the plug in and insert the transducer for special occasions only...like a race...

I have a tube of Desitin (baby diaper rash ointment) that I coat the paddles with to inhibit growth. Even with the Desitin the device won't go much longer than 5-6 weeks before it needs cleaning..... so over the years I've found the gps...speed over ground.. data to be satisfactory for my cruising needs.

It seems all the newer devices... mine is at least 25 years old... have a self sealing feature built into the thru hull to allow for more conveninent cleaning. I'd be interested to know how well that works... because eventually I'd like to upgrade.... and eventually have a boat full of integrated instruments.

 

[RichH]

It seems all the newer devices... mine is at least 25 years old... have a self sealing feature built into the thru hull to allow for more conveninent cleaning. I'd be interested to know how well that works... because eventually I'd like to upgrade.... and eventually have a boat full of integrated instruments.

Yup, most of the newer 'plastic' thruhulls used for speedo, etc. transducers have (what I call) a 'clam valve' that closes by water pressure when the transducer is pulled. With such you dont get the massive 'fountain' of water entering the boat but do get about 5-10% of the amount of water in comparison to not having that 'clam valve' (actually a thin walled 'mitral' valve). Good but not 'perfect', and still needs that dummy-plug to be inserted when taking time to fully clean the paddle wheel, etc.
The downside to the 'plastic' thruhulls is you cant use solvent based bottom paint on them ... as such can soften / reduce the strength ... and leaves you no choice but to use an inefficient water based 'transducer paint' on the exposed transducer and thruhull and which has the same anti-fouling effectiveness of using 'owl piss' -- not worth the trouble.
;-)