My speedometer on my 2010 Sea Hunt has always worked fine. Now it doesnt so I guess I have an obstruction in the tube. I have tried to blow out the tube from the speedometer backwards. No luck. Question is where does it get water from on the Yamaha motor? I have had problems with wasps/bees clogging the engines pee hole so that may be the issue there as well.
I have the same problem with my yammie 150. On the lower unit in the very front you will see a small hole. That has some debris in it. I use the very fine drill bit by hand and clean it out that way. DO NOT use a drill with the bit just twist the bit in slowly by hand.
Chad
Cobia 256 Express
Pulled by a Dodge Ram 3500
Those things are notorious for getting clogged. Some days mine works other days it doesn’t. I like having one on my console for aesthetics but, I rely on my GPS for actual speed.
you can also try running a short pc of weedeater line through the hole while twisting.