speedometer will not work what can I do?

[grizzly1733]

I have a 1996 Rinker Jet Boat with a merc 120XR sport jet engine in it. I bought the boat used and the speedometer never worked. The previous owner broke the pick up on the back of the boat off. He then replaced it with a new one but it doesn't work. What can I do? How does it work do I need a specific kind of pick up?

 

[Boatist]

Re: speedometer will not work what can I do?

Most all of them use a standard pickup. Make the air hose is connected and not leaking. Make sure the pickup is in the down postion, most have a postion where pickup will kick up if hit something. Check the hole in pick up and make sure it is not plugged up. Blow air into hole and see if speedo moves. Blow air into back of speedo and see if speedo moves ir not replace speedo. Check hose from pickup up all the way to speedo for leaks and crimps.

 

[SB]

Re: speedometer will not work what can I do?

Most speedometers are inaccurate especially at low speeds. Try an inexpensive handheld GPS. I got a Garmin eTrex for $120 and it is very accurate, even at low speeds. It is a great help in tuning and making adjustments.<br /><br />Scott

 

[grizzly1733]

Re: speedometer will not work what can I do?

How much pressure do you have to have inorder to get the speedometer to work. When I tested it I could not create enough pressure by blowing in the line inorder to get it to move. But I can get the speedometer to move if I blow air in the line with an air gun. Is the speedometer shot?

 

[Bob_VT]

Re: speedometer will not work what can I do?

Standard marine speedometers are fed pressure through a plastic line which is fed by the pitot on the transom.<br /><br />You stated you replaced the pitot now I would inspeck the plastic line for kinks or breaks working you way to the speedometer itself.<br /><br />If you like you can usually remove a speedometer by loosening the two nots and remove the bracket from the rear.<br /><br />Test your speedometer at your speedometer bypassing the line. My speedo does not indicate anything less than 20 mph. My GPS has the ability to track the speed of a carpenter ant.<br /><br />Go GPS.<br /><br />Bob

 

[Lark40]

Re: speedometer will not work what can I do?

Don't bother with repairing a water tube speedometer. IMHO, they are obselete, inaccurate technology. <br /><br />Use a GPS, either handheld, or part of a chartplotter, to get accurate speed readings.

 

[bryont]

Re: speedometer will not work what can I do?

Well I have found by using my air compressor and regulater was suprised that each MPH is very close to Each PSI. I had the same problem as you are having. I found numerous things wrong in my case. First I have a Yamaha I/O set up and the pickup for the speedometer is at the leading edge of the lower unit and there was a coupling that the hose was split on the coupling nipple. Fixed that no good. So I took the hose off the guage and poured water down it and forced it out backwards toward the back of the boat. I put the other end in a jar so that I could see if anything came out. Well it was clogged up. Put it back together and used compressed air and checked the guage to 50 mph. Good to go so I thought. Got it on the water that weekend and it still did not work. So I pulled it loose from the guage again and sucked on the line just a bit hoping for the best. Has worked ever since. I borrowed a friends GPS unit and found out that it was within 1 mph of my guage reading in the upper range. Didn't think that was bad. I know that they are not very accurate but I just hate to be running on the lake with it not working. Bugs the crap out of me so I was determined to fix it. Must be a mental thing.<br /> Be aware that yes I work on all types of things but I am fresh to boating. So I must put in the newbie disclaimer. Good luck.

 

[flashback]

Re: speedometer will not work what can I do?

I have a fish finder with a paddle wheel that does ok I guess. gotta 21 footer with a 350 chevy that goes 48 mph at 4300 rpm WOT according to the fish finder.......