Nordskog speedo reading too high ?
 

I have an older (1986) Norskog speedo the is reading almost 10mph to high. The pitot extends about 3" down.

Any ideas?

Is it a metal pickup? Maybe you can bend it till it reads right. I have a gaffrig pick up. When it is brand new (unbent) it reads +5. I hit something in the water that bent the pickup back. It now reads right on. I hit something again, bent it some more and it then was reading low. So, the more it is bent the lower it read. I traced the pickup on a piece of paper when it was reading right. Now I can if it gets bent more, I can bend it back to the optimum angle.