Thanks for your comments , I did connect and test the new level sensor throughout it's range before inserting it in the fuel tank and it did appear to show correctly , all the bars on the gauge did operate as they should , weird 

Thank you all for your comments , looks as though I'm going to have to put up with it 

I thank you for your help , everything else is functioning correctly ie Tail lights etc , I did connect and operated the new level sensor before inserting it in the fuel tank and it read perfectly throughout the range of the fuel gauge ( all the bars on the gauge ) , really weird one , just wish I could get to the bottom of this annoying problem Grrrrrrr 

Anybody out there can help ? Please !!!!!!!!!

Can anyone help please , I have just bought a CF 450 L Quad , when the fuel tank is full the fuel gauge does read full and will gradually drop as fuel is used , BUT when the tank is well over half full the gauge will suddenly show empty and starts to flash even though there is around 10 litres of fuel in the tank , I have have fitted a new fuel level sensor but the same problem still exists , any suggestions / help would be much appreciated , thank you.