speedo inop on 1999 four winns

[imported_mikeman]

hello

my speedo only registers 10 mph even though the boat is going flat out,at slower speeds it does not register at all.ive checked out the hole in the pick up that goes in the water and it clear.
im not sure what to do next

my boat is a 1999 four winns 180 horison with a 4.3L volvo engine

thanks

mike

 

[Silvertip]

Re: speedo inop on 1999 four winns

Make sure the tube to the gauge is not pinched. Disconnect the tube at the gauge and at the pitot and blow backward through it. Replace it if its restricted.

 

[imported_mikeman]

Re: speedo inop on 1999 four winns

thanks for the info but what is a pitot

and if it is resticted the pitot is what i replace ??

thanks

mike

 

[Boatin Bob]

Re: speedo inop on 1999 four winns

Mike...have a look at this picture (typical pitot) you should have something like this mounted on the outside of your transom (unless you have a digital speedo with a paddle wheel?) about halfway up an air hose is attached that runs all the way to your speedo. The way it works is there is a tiny hole on the bottom that picks water up, the faster you go it pushes the water further up the tube, as the water goes up the tube it compresses the air which in turn makes the speedo work. That's why it's suggested to make sure pitot is clear and the tube by pulling the hose off the speedo and blowing down the hose to see if any air comes out the pitot.
Pitot

 

[Silvertip]

Re: speedo inop on 1999 four winns

The pitot may also be an integral part of the outboard lower unit or an I/O lower unit in which case you would not have the external pitot Boatin Bob posted. Principle is the same however. Follow the tube back to wherever its connected. This is a simple device. Either the pitot is plugged, the tube is kinked or plugged, or speedo head is bad. If you have a paddle wheel (electric) speedo, none of this applies. Either the paddle wheel, wiring, or head is bad.

 

[Boatist]

Re: speedo inop on 1999 four winns

Also the pitot is not kicked up. They are designed to kick up if they hit something. So make sure it is pointed down below the hull like the one in the picture.

 

[tayloe]

Re: speedo inop on 1999 four winns

This post does not pertain to mikeman's issue, but is on the topic. Speedo issue on my 2001 Larson 190 LXI. I allowed my boat to sit on the sany bottom of lake sommerville last weekend. I didn't think it would do any harm...until the next morning the speedo was not working. I have the electronic paddle type pick-up. The assembly is mounted on the bottom edge of the hull next to the out-drive. I don't think it is a wiring issue bc it was working fine the day before I left it 'beached' in three ft of water overnight. Could sand get into the assembly? Should the paddle wheel spin with little to no resistance? Can I find a replacement paddle wheel to trial and error with? I am not sure what the cause here was. Need some clarity.

Thanks.