Help Identifying Part- Transom Mount

[BeMorWize]

Hi Guys,

So this weekend I decided to remove my old fish finder and I also removed something I thought belonged to the fish finder but it didn't (mistook it for the temperature reader?). The fish finder was a Humminbird 300TX.

I need help identifying this part as I don't know what it is or what it does? Please forgive me if it is a newb question, just haven't run accross one of these before.

So this part came off of the transom, it was attached right next to the old transducer, about 5 inches to the left of the transducer. There is a black maybe 1/16 hose that attached to the opening 1inch above my thumb pictured below. The black hose runs to the console area (about 8ft long?) but I don't know/cant see where it ends at, thus I have no idea what this part is for or IF I NEED TO PUT IT BACK IN THE TRANSOM?



This came off of a 14crestliner side console with live well, etc. Maybe this part belongs to the livewell? or is it the speed reader for the Odometer?

Thank you for your help...

[cutbait]

Vacuum for the speedometer.

Pito tube I believe..

Throw it away, they work terrible anyway

[cutbait]

google pitot tube

[BeMorWize]

Thank you Sir,

So fast with your response, I actually just pm'd you again (sorry)

If I throw it away, would the speedometer work normally still? Or do I need to plug the end of the Pito Tube?

My concern is what's to keep the vacuum pressure for the speedometer if this piece is no longer is use?

[BeMorWize]

Thank you Cutbait, just googled it....

Still confused, I understand why its there, my only question is, now that it's removed, do I need to replace it with another speedometer? (will the boat still know how fast its going since this is now removed??). I haven't tested the boat out after it was removed this weekend so I have no idea if the mph odometer is working, I guess that's my other question. Obviously, if the mph still reads on the odometer, then I can just throw the vacuum thing away and call it a day.

From what I read, it holds the pressure in the hose

[cutbait]

If you MUST have a speedometer gauge working on the console, you must reattach this to the transom. If you do read up on it as you have to mount this correctly or it will be inaccurate.

Now, inaccurate is key, because this is exactly what these are. I vote that you just throw it away, cut your vacuum line off and use a GPS fishfinder for speed. But if your goal is to have an "never accurate" speedometer then put it back on.

Your gauge will not work without this back on and installed correctly and the vacuum line hooked up.

You said "vacuum pressure"... google the difference between vacuum and pressure. They are opposites, like day and night, plus and minus.

The speedo works because the flow of water past the opening of your pitot tube creates a suction {vacuum} which your speedometer reads. The faster the water runs by your pitot tube, the more suction {vacuum} is drawn in the vacuum line, which your guage reads... So the faster you go, the higher the vacuum in the line, the more the needle on the guage turns, indicating speed on the face of the gauge.

Again, notorisly inaccurate too

[BeMorWize]

Got it!!

Much appreciated Sir, thank you for taking your time out and helping me figure this out Cutbait.