On Mon, 18 Feb 2008 08:01:05 -0800 (PST), nfisherman
wrote:

My speedometer is not working. I have narrowed the problem down to
the inlet for th pitot tube in the gear case. I have removed the gear
case and when I put air pressure on the tube toward the dash, the
speedo needle moves. I cannot blow air in the other direction into
the gear case. It's plugged tight. I can't see any clogged holes on
the exterior of the gear case. Does anyone have any suggestions
before I give up and live with my GPS for speed?. I know the GPS is
more accurate anyway, I just like to have all of the console gauges
working.

I've seen this before, but not on a Yamaha.

What's probably happened is the tube from the pitot intake is blocked
or pinched - more likely blocked by crap - salt, mud, sand, etc.

The best way to clear it is to use thin SS wire - like trolling wire -
or, the way I did it on an old Evinrude, SS welding wire - the
thinnest you can get which is pretty thin.

Either that or grab a air hose and use pressure to clear the line.