easiest way to clean Speedometer tube

[nottelybill]

I have a 2001 150 hp Yamaha and speedometer does not work. I am pretty sure it is a blockage in the supply tube somewhere. So what is the easiest way to clean it out? I have not yet pulled tube of the back of speedometer to check there.

[robert graham]

How about a section of monofilament/weed eater line inserted into the hose?...

[boscoe99]

The pitot tube on the leading edge of the lower unit is the most probable place for a blockage to occur. You might hit a rotten log for example and it will block the tube.

Take a 3/32nds drill bit and gently insert it into the pitot tube while turning the bit clockwise. This will help to auger out any debris there may be in the hole. After you have gotten the hole cleaned, as best as you can, go into the engine pan and find the connection point for the tube that runs from the lower unit. Disconnect the tube and blow air downwards to clear any remaining debris out. Don't forget to reattach the hoses ends together.