ox66 2002 150hp speedometer hose

[anthropisces]

Folks,

While changing the water pump on my 2002 ox66 150, I cracked the plastic NPT fitting that has the hose barb, that attaches to a hose that leads to the speedometer (I am told).

I installed the new NPT fitting and after examining the hose I think it should be replaced also. It is very hard down by the fitting and looks pretty old elsewhere. My question is whether there is anything special I need to consider when running the new hose.

There must be a pressure transducer in the speedometer, but is that tube supposed to be filled with air? If so then the length of the hose would seem to have an effect on the reading because of the compressiblity of the gas. The speedometer hose is probably going to be 15' long when all is said and done.

Thanks