Check a Faria mechanical speedometer's operation if it sticks. Loosen the nut or nuts that hold the speedometer's back clamp in place. Ensure the speedometer is not attached loosely to the panel. Check for sharp kinks or bends in the tubing that runs from the speedometer's head to the pitot tube, and straighten sharp kinks and bends you find. The pitot tube is where water goes in so that speed can be measured. Check the inlet hole of the pitot tube for blockage, and clear the blockage.
Check the speedometer's back and pitot tube for loose connections and the tubing for breaks if your mechanical speedometer does not register speed. If the device has loose connections, then remove the tubing, cut it back by about 1/2 inch using a sharp knife and reattach it to the speedometer.
Calibrate the speedometer if it is electronic. Test it by comparing its speed reading with that of a Loran, global positioning satellite or radar gun while running your boat in calm water. Turn the six-position selector switch located at the rear of the speedometer case to "3" or "4." If the speedometer reading is higher than it should be, then increase the setting of the six-position selector switch until the device is accurate. If the speedometer reads lower than it should, decrease the six-position selector switch setting.
