Airmar Paddle Wheel

[coveman]

I have an Airmar Paddle wheel speed transducer fitted to the boat, which is probably quite old, so not sure of the model. Both the transducer and the bung have one rubber 0 ring on each. However, there appears to be a second groove on both and I'm wondering whether there should be two rings on each? Thanks in advance for your views.

 

[Refueler]

Not sure if its Airmar or not - its Echopilot ... but probably is - Airmar produce for various brands .............

Here you see similar ... one O ring ... two grooves ....

 

[coveman]

Thanks - yes mine is very similar so guess the one O ring is ok. I wonder what the second groove is for?

 

[Refueler]

maybe a second O ring if felt necessary ?? But my Nasa (for my motor boat) .. Echopilot in my 25ft Motor Sailor and the two in my 38ft racer are all one O ring ...

Here's my Racer paddle wheels extracted for cleaning !! you can see a single sealing ring near securing cap on each ... (yes I know disgusting !!)