Petrol gauge dilemma

[richmford]

I'm normally a glass half full bloke but on my Rocket the fuel gauge shows the tank is empty when in fact its only half empty.
Previous owner fitted a after market clock and fuel gauge and both are not working correctly. When the fuel gauge is nearing empty the light on the speedo also lights up indicating running close to empty, in reality I have half a tank left.
Has anyone had similar issues and is there a fix? i assume there is a sensor in the tank and I'm wondering if when they fitted the after market gauge they set the sensor incorrectly.
If that's the case is there a fix?
As for the clock I can only guess that's a wiring issue, it would be great if the bugger worked but the fuel gauge is my main goal to get sorted. any help would be appreciated.

 

[TURBO200R4]

I think that most of the gauge lights goes off at about half full/empty
you would have to bend the float rod and it is pretty easy to screw it up.

 

[Tripps]

When Carpenter did my engine work, they gave it back and it's only gone to 5/8 when full ever since. I called them, they said we didn't do anything that could have caused that. SMFH, you changed the fuel pump, didn't you? They went down a couple notches as far as my opinion of them after that. I have to assume that they bent the fuel guage rod, I just lived with it since then