speedometer baja 212 islander 2000

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Stick your head under the console and check the back of the speedometer. You will find a black tube (no -- it's not an electrical cable). That tube runs from the speedo back to a pitot that can be in either of two places. 1) A plastic unit bolted to the transom or 2) the pitot on the lower unit of the outdrive. The most common causes of speedo failure are a kinked tube, a plugged pitot, disconnected pitot, or a pitot that has broken off or is flipped up. In operation, water pressure in the tube compresses air in the tube that unwinds a Bourdon tube linked to the speedo needle inside the speedo head.
 

kjsAZ

Chief Petty Officer
Joined
Jun 15, 2012
Messages
433
The pitot can be part of the lower unit. Would be good if you post info what engine/drive you have. Then it's just a hose which connects to the inner tubing somewhere further up which runs forward to the gauge. It's a pretty small hole with maybe 2mm diameter facing forward from the rear corner of the lower unit. These holes get plugged by debris or dirt very easy and then the speedo doesn't work any more or shows far to low. If the hose is broken inside the boat water will come out in a nice stream.

As they are often wrong or malfunctioning I don't like them at all. I disconnected the hose completely after it failed for several times and use GPS instead. Doesn't give you speed over water but it works for speed over ground. Now I only have to replace the gauge with something useful (a vase with a nice flower??).

Edit: just checked. You have a Mercruiser I/O. That means that the pitot tube is just the small hole I mentioned above. Most likely clogged and a PITA to clean. The hose comes out at the bottom of the upper unit (or top of the lower) and goes through the stern.
 
Last edited:
Top