Speedometer tube splice.

Dave-R

Chief Petty Officer
Joined
Mar 18, 2008
Messages
441
The speedometer on my 350Mercruiser magnum did not work when I first bought the boat.After checking it out, I found it was cut under the drive. So I used a splice kit to repair it. I then blew from the gauge out to the drive, where I had it disconnected. Also blew backward thru the drive unit, and flows seemed good. Still did not fix the problem.
I ordered a new speedometer, but I still wonder if the splice was okay? Anyone have a similar problem? Thanks Dave R.
 

Grub54891

Vice Admiral
Joined
Jun 17, 2012
Messages
5,908
Re: Speedometer tube splice.

The drive itself has the passage that could be plugged,It's right on the front of the lower unit,a small hole. Blow air in from the bottom up,with the speedo hose disconnected. Any debris should get blown out,sometimes ya have to poke it with a small wire to break it loose.
Very seldom does a speedo unit go south,but it does happen.
Grub
 

Dave-R

Chief Petty Officer
Joined
Mar 18, 2008
Messages
441
Re: Speedometer tube splice.

Thanks Grub: Did that. Also blew both ways and seemed to have good flow.
 
Joined
Feb 17, 2012
Messages
2,906
Re: Speedometer tube splice.

a can of compressed air that you use on a keyboard works great for testing. I have used micro sprinkler connections on my speedo tube as It got in the way where it comes out of the transom so a 90 degree sprinkler connection worked fine with a few tie wraps for extra security and it removed the stress to the tube where it use to be bent (new transom so I drilled the speedo tube real small instead of a large hole to allow for the tube to bend).
 
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