Speed dial problems

[PaulClioSport]

A mate of mine has a ph1 172, now his problem is that the needle of the speed dial sometimes drops down to 0mph and after a few sec's it comes back to live! Anyon got any idea what this could be?

 

[MicKPM]

Hallo - Speedo sender in the back of the gearbox matey... a fairly common issue.

Mick

 

[PaulClioSport]

Thanks mate! Much appreciated!