What’s this tube for?

[Fisherman Rob]

Anyone know what this grey painted rubber tube is for that goes from the motor mount into the lower unit? I had my water pump replaced and it came back from the shop disconnected. I didn’t notice until after taking the boat out in the ocean. I reconnected it, but not sure what the consequence may be. Shop thinks it’s an old speedometer tube. Motor is a 1996 Yamaha 115.

 

[kingblazer84]

Anyone know what this grey painted rubber tube is for that goes from the motor mount into the lower unit? I had my water pump replaced and it came back from the shop disconnected. I didn’t notice until after taking the boat out in the ocean. I reconnected it, but not sure what the consequence may be. Shop thinks it’s an old speedometer tube. Motor is a 1996 Yamaha 115.

I’d 2nd the speedo tube

 

[Fisherman Rob]

Also, my tach only registers zero RPM now. I suspect some wire somewhere is disconnected. Any ideas on where to start?

 

[easydoesit]

Also, my tach only registers zero RPM now. I suspect some wire somewhere is disconnected. Any ideas on where to start?

Follow your Speedo tubing from the motor. I believe it operates on air pressure to the Yamaha gauge.

 

[Fisherman Rob]

Follow your Speedo tubing from the motor. I believe it operates on air pressure to the Yamaha gauge.

The tach works on air pressure?

 

[easydoesit]

The tach works on air pressure?

The speedometer works on air pressure. This was the OP’s first question.

Tach is electric, sorry, mixed the two inquiries.

 

[RiverBoy]

i’d be taking it back and telling them to make it right. sheesh.

 

[Fisherman Rob]

OK a little digging on the internet often reveals the answer! It is definitely the speedo tube, and so I don't think any damage would have occurred while disconnected :

Now about that Tach...

 

[profisher]

I plugged mine off because they plug up all the time and never work..I use the speed function on my plotter to know how fast I'm going...way more accurate and reliable.