Need some tips for Raymarine knot meter.

[Slade]

I have a new Raymarine Bidata knotlog depth finder. Installed with no problems and for the first month everything was great. Very happy with the performance. Seems the knotmeter has decided to quit. Depth finder works fine. Where we are has some light moss like gunk that sticks to everything. We have new bottom (VC-17) paint on and the gunk wipes right off. I have been over the side and the paddle wheel moves ok by hand but does not register on the display.

Any thoughts on what might be up? I have checked the connections and all are tight, dry and clean. I haven't pulled the sensor yet...nervous about the exchange and the flood of water I can expect.

Other than that I've been pleased with the instrument. Have the flux gate compass and that works great as well.

 

[orion]

There is no substitute for pulling the knot meter and putting the plug in the opening. It seems like a lot of water, but if you are quick it is only about a quart. Once the knot meter is pulled you can give it a complete cleaning and spin the paddle wheel by hand. You should have someone near the readout to tell you that you are registering speed on the readout when you spin the wheel.

 

[bob328]

raymarine knotmeter

I have the same unit. Sometimes the wiring loosens at the connector bar. The wires are small and sometimes it takes Otherwise you should be able to pull the paddle wheel and quickly put the plug in. Make sure the paddle wheel spins freely. I used tranducer paint and it will work for about 9 months without problems. Fair winds!

 

[Ted]

Need some tips for Raymarine knot meter

I agree that you should pull the transducer to do a thorough cleaning. On a side note, there are through hull fittings for the transducer that have small trap doors which automatically close to greatly limit the amount of water that enters the boat when the transducer is removed. I think I read somewhere that the paddle wheel has a magnet in one of the vanes and this can somehow loose it's magnetism and cause the transducer to fail to give readings. The fix was to replace just the paddle wheel. Contact Raymarine or visit their website as I'm sure there is a way of testing the output from the transducer wires to determine what's wrong.

 

[Ron20324]

I have one of the units with the flapper in the thruhull. I get one or two cups of water, but always have a towel on the floor to catch it. In the summer, if I leave the wheel in place more than a week it will start to clog with algae. SOMETIMES it will clear as I sail, but if 2 weeks of growth are there, I have to pull it and clean it with a brush. At the end of a sail i'll consider how long it will be before I need it again, and maybe pull the wheel out as a preventative measure. As said, spin the wheel and see if someone can see a reading. I put some lube on the o ring of the wheel and the dummy plug before insertion. Pull the wheel with one hand as you have the dummy in the other to place rapidly. You get less water inflow if you can do this under way.

 

[Slade]

Thanks for the input all. I kinda thought pulling the transducer would be the answer, but not having done it yet seems intimidating. Just have to bite the bullet and give er a shot. I'll let you all know how it goes..wish me luck!

 

[Slade]

Hi all,
You all were right..pulling the transducer is no big deal. I've done it 3 times now and you could eat off it now..I wouldn't, but you could. The temp gauge and depth work wonderfully still. Just that recalcitrant paddle wheel. Spins like a top but no register. I have gone bow to stern checking the wire to no avail.

Next step is to contact Raymarine (still under warranty) and see what they say. Hopefully it's just a goofy paddle wheel so I don't have to rerun the wiring.

Anyway, thanks for the suggestions and help. Gave me the confidence to "just do it" pulling the plug.

 

[Bill Roosa]

Try this, go to the knots log (odometer) screen and see it it is showing increasing distance traveled. If you have the sensor pulled you can note the current reading and then spin the paddle wheel for a few minutes. It spins A LOT to get even 0.01 NM so take a long smoke break while you do it. If it is showing a change then the sensor is probably ok but needs recal

 

[Slade]

Will do Bill. Thanks for the idea. Will be able to spend some days on board this week (about time) with buddy so we'll give it a shot.

 

[Deadhead]

I removed a barnacle from my wheel yesterday morning. Back in business.