MPH

[PRO V LE]

clean out the debri in the pitot tube/line

[Monarkman]

^^I agreee. Check for any kinks or cuts in the tubing and make sure everything is tight. You can disconnect it at speedometer if you can get to it and blow air back through it. Don't use a lot of pressure or you could blow something apart.

[Shimano4Life]

I agree with both of the gentlemen that have already posted. Remove the rubber line from the pitot and from the back of the gauge itself. Then blow air through it if you have a compressor and an air gun. If not, take it to the nearest gas station and do it. The rubber line should be connnected with zip-ties. If not, be careful when removing them -- you could break the nipple off the pitot or even worse, off the gauge.

I've done this a million times, mostly at the boat dealership I used to work at.

What kind of motor do you have? What year and what make? The speedo pickup could be located on the lower unit. If it is, remove the rubber line from the gauge and try to blow it out. If this doesn't work, remove the line from the top front of the cavitation plate on the lower unit and try (again with the line off the gauge).

Hope this helps you out.