tach issue and speedo

[Bang Boat]

tach shows correct idle but when cruising bounces around up to 4kish and at 21mph (gps) reads anywhere between 35-43ish.when it was working we saw like 2800
2001 21i

speedo is not working but what are the pieces at the back called that measure pressure? Pitot tubes? anywhere I can find them online>> mine are broken off.

Im the first mate on my buddies boat and we are looking to get his new boat all in order.

[TeamAllen]

Welcome to the site.

Is the plastic tubing tubing broken or pieces of the speedo?

They make a new GPS speedo that you can replace with.
http://www.perfectpass.com/images/pr...cisionStar.pdf

Or a more less expensive replacement option.
http://www.boatersland.com/far-32908.html