Speed Odommeter

EARLS BOAT

Petty Officer 2nd Class
Joined
Aug 2, 2008
Messages
143
Where Do I Begin To Try And Fix A Speed Odometer On A 1989 Bass Tracker? I Feel There Should Be Something On The Transome With Wires But All There Is Is A Transducer For The Old Dept Finder That Does Not Work Either.
 

G_Lipe

Cadet
Joined
May 4, 2007
Messages
24
Re: Speed Odommeter

The speedo pick up will be on the lower leg of the motor to fix it you will probably need to pull the tube off the back of the gauge and blow it out these tubes usually clog with crap every year

mine has been nonfunctional for 2 years but when they work they are not accurate it is usually at least 5mph different then my gps
 

Nandy

Commander
Joined
Apr 10, 2004
Messages
2,145
Re: Speed Odommeter

Depending on what gauge do you have. If it is electronic there has to be a cable going to the transom. There will be a paddle wheel style sensor that is attached to the transom much like your transducer and it turns as the water pass by. That indicates the speed. This is somehow accurate system.
If analog you will have tubing coming from the back of the gauge. If you were to put a compressor of blow on it you should see the gauge goes up. The tubing goes to a bracket similar to the transducer and that bracket is holding a generally L shaped "sensor". The way the sensor works is that as the water pass under your hull it pushes and compress the air inside the tubing. This makes the gauge goes up. Some motors has the sensor in the lower unit and therefore the tubing goes inside the cowling with the other cables for controlling the motor. If this is not too clear try to take a photo of the gauge from the behind, the transom and give us your motor make and model... That will talk volumes to us...
 

EARLS BOAT

Petty Officer 2nd Class
Joined
Aug 2, 2008
Messages
143
Re: Speed Odommeter

Ok I Will Try To Do All That Tommrow It Is Dark And Stormy Right Now. I May Not Be Able To Post Pics. I Have Tried Before And It Ask For The Url Of The Picture Whatever That Is, But I'll Try.
 

EARLS BOAT

Petty Officer 2nd Class
Joined
Aug 2, 2008
Messages
143
Re: Speed Odommeter

My Gauge Uses Water Pressure But I Cant Find Where It Hooks To The Outboard.
 

Nandy

Commander
Joined
Apr 10, 2004
Messages
2,145
Re: Speed Odommeter

Again, what motor? Brand/model. As far as working on water pressure that is half true. The water pressure makes the air pressure in the tubing raise and that is what makes the gauge move. Did you see any tubing attached to your gauge or a port for tubing? I think the i/d of the tubing is not even 1/4. If you can't take photos look at the back of the gauge and try to describe the connections you will see. Regardless of electric or analog you should at least have a 12 volt connection for the lights. Let us know.
 

EARLS BOAT

Petty Officer 2nd Class
Joined
Aug 2, 2008
Messages
143
Re: Speed Odommeter

nandy, the outboard is a 1989 70hp evinrude. i thought that the 1/4 inch line from the speedometer connected to the lower unit of my outboard somehow. :rolleyes: after reading tashasdaddy's reply i see that it conncets to what is called a pitot am i correct? are am i still in the land of the big dummies?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Speed Odommeter

Look at the back of the boat. If you see one of these, that's the pitot. Connect the tube to it. Don't think the Johnson motor had a built in pitot so you have no other choice. The pitot in the picture is the white plastic part on the left side of the boat.

Ducer-Speed.jpg
 
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