Digital speedo showing 75

[Keysfishfinder]

Installed a new to me digital speedo as my old one was faded out. The new one looks great when I toggle on 12v but it shows speed of 75mph and the miles keeps slowing going up. I only toggled on power did not start engine.

Next I powered on engine and same readings

03 Yamaha HPDI 225

Any ideas are appreciated

Thanks

[99yam40]

slow down 75 is too fast .

Really never heard of this happening.
is the speed reading coming from GPS or a pressure sensor from lower unit?

[Keysfishfinder]

Speed is my drug !!!

No GPS attached just factory wires. Old speedo was ok just very hard to read. Not sure if this could happen when moving the tube from old speedo to new?

[99yam40]

disconnect the tube and see if it changes.

tube or lower unit opening may be plugged up and has pressure blocked in for some reason or the gauge is bad.
is it new or just new to you?