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Alrighty...where do I place the speedometer pick-up device on the back of my boat? This is the plastic device that attaches to the transom and has the flip down thingy. The tube that goes to the speedometer on the dashboard attaches to the flip down thingy.

Do I place it perpindicular to the water's surface or perpindicular to the bottom of the boat's surface?

Does it matter where it is located on the transom's width??? near the center?? closer to one side or the other???

Andreas

Andreas,

The "Pitot" tube, as the "thingy" is called, is mounted on the transom with the flip up Pitot tube parallel to the vertivcal ceterline of the transom and keel. Mount the unit on the transom and loacted along the flat portion of the hull bottom where there will be the least amount of turbulance caused by the motor, keel or sister keels. Pitot tube when flipped down should extend a couple inches below the bottom of the hull so it will pickup the pressure of the water running under the hull to cause an increase in the air pressure within tubing which in turn causes the needle on the speedometer to move. The speedometer is nothing more then a pressure gauge calibrated to MPH in lieu of PSI.
Locate the Pitot unit as close to the bottom of the transom as possible with the small hole in the flip down portion facing forward when extended down past the hull bottom surface. Run the tube up as high as possible along the transom surface before drilling thru the transom to bring the tube inboard or if you bring it thru the transom lower down be sure the tube is sloped downward fromthe speedometer location toward the transom. This will eliminate water from being forced up into the tube and causing a problem if it gets traped in the tube. Try to keep the tube sloped toward the transom when run with in the boat to aid in the mositure that gets into tube to drain out of the tube.

One speedometer unit I salvaged off an older boat had a brass expansion tube approximately 7/8" in diamaeter and 10" long with capped ends with small christmas tree type fittings on the capped ends for the small diameter tubing to install to. This allowed any water driven into the pitot tube and tubing to collect here and drain out when the boat was stopped or out of the water. The unit could either be mounted inside or outside of the boat. If the expansion unit was mounted inside the transom the tubing running from the pitot tube came thru the transom about 2" to 3" above the pitot tube mounting base and below the loaction of the expansion tube.

Hope that answers you question.

Phill

Thank you! Thank you! Perfect!

Andreas

Got it installed yesterday. Went for a cruise and it worked wonderfully!

Andreas