speedo not working, help?

[44motion]

I have a 94 alumacraft v17 phantom. The speedo used to work fine but couple weeks ago, it just didn't kick in while on the go. I've check the plastic thing at the rear of boat and there's no clog. Also checked behind the speedo gauge where the tube plugs in, and it was loose and there's little droplets of moisture (water?). I plugged it back in and hope that was the problem, but nope. The RPM gauge still works. Anybody want to shine in on this? Thanks.

 

[UncleWillie]

Take the tube off the gage again. Blowing ito the tube should make the water in the line blow out the Pitot tube on the transom.
Put the tube back on the gage and remove the other end from the pitot tube.
Blow into the tube at the transom end. A healthy set of lungs should display 10-15 mph on the gage.
Make sure the Pitot Tube has not been bumped and is still pointing down and is in the water while on plane.

 

[44motion]

I did blow into both ends but didn't do it hard enough to read the gauge. and no the pitot tube is not bent or bumped. will try again..thanks

 

[crb478]

If the speedo does not move when you blow into it, it may be bad but this is rare. Most of them are inaccurate, but they rarely wear out. Try blowing compressed air through the line from the speedo side back. If it is clear start looking for leaks in the line.

 

[Watermann]

You may end up needing to replace the 20 year old tubing and pitot tube. It's very cheep to get the new tubing and pitot, under 12 bucks.

http://www.iboats.com/Speedometer-P...409836438--session_id.088764569--view_id.5042

 

[44motion]

Cool thanks for the info.

 

[rbh]

Just make sure that the pitot tube is in the down position as they can rotate up if bumped/pushed and will not work

 

[44motion]

If the speedo does not move when you blow into it, it may be bad but this is rare. Most of them are inaccurate, but they rarely wear out. Try blowing compressed air through the line from the speedo side back. If it is clear start looking for leaks in the line.

OK, so I tried blowing into the tube again with someone else looking at the speedo gauge and it did move to 15 mph..but still doesn't move when on the go in the water.

 

[crb478]

There is a hole in the tubing or the pivot tube is leaking/blocked