Rev counter going weird !!

[Draad]

My rev counter seems to be jumping up and down ... not sure how to explain but when I rev the bike the needle seems to not know where to go ..sudden movements ..not smooth !!!

Could this be an earth problem or what ?

 

[Welsh]

 

[Ganjora]

 

[Beebop]

 

[Stofdonkie]

 

[Mambat]

 

[Stofdonkie]

 

[Mambat]

 

[Coxwain]

 

[DirtRebell]

 

[Red Adventure]

 

[Draad]

 

[ATysterperd]

 

[Welsh]

 

[DirtRebell]

 

[ATysterperd]

 

[Welsh]

 

[DirtRebell]

 

[Coxwain]

 

[ATysterperd]