What Will Cause Speedometer to Not Register Properly

[ghostrider]

What would and or will cause a speedometer to malfunction? I took my boat out for the first time this year and discovered that the Speedometer is not working properly. I was running 3/4 throttle and was only registering about 34 mph and another time was running wot and registering 32 mph. The speedo worked the last time it was run in December. Please Help!<br /><br />Ghostrider

 

[mellowyellow]

Re: What Will Cause Speedometer to Not Register Properly

disconnect pick up tube and blow out with <br />compressed air. prob. sucked up some muck.<br />good luck,<br />M.Y.

 

[ghostrider]

Re: What Will Cause Speedometer to Not Register Properly

Mellowyellow, Thanks for the info you were right about the air through the pitot tube. I put my air gun on the tube and when I blew the air through I could hear air escaping. I checked the line and found there was a split where the line had rubbed/chaffed through. I spliced the line and blew air through again and the problem was fixed. Thanx again!<br />Now, can you tell me why my steering is stiff at 3/4 to WOT?<br /><br />Ghostrider