How to repair/replace a fuel gauge stuck on Full?

I have a '79 KZ1000ST. I was riding the other day on my way to the gas station, when all of a sudden my fuel gauge went from 'empty' to 'full' w/o adding any gas. I knew the bike was close to empty so I filled it half way and still the fuel gauge reads Full. I disconnected the fuel gauge electrical connector and of course it drops to empty with ignition on. When I plug the connector back in, fuel gauge slowly returns to a full reading. Does anyone know what went wrong here, what to look for or what part I need to replace this so I can get a working fuel gauge again? My first guess is a fuel level float somewhere inside the tank that got stuck and needs replacement. But then again, I'm no expert and this is where I ask for your help/expertise. How hard is it to fix this unresponsive fuel gauge problem and what should I do? Any thoughts, suggestions, or help finding the right replacement? Thanks.

On, Fuel guages are goofy. the sender (inside tank) is just a big open wired rheostat. the float/arm rises/falls making contact (hopefully) on exposed high resistanc wires on a vertical post. somewhere later (depending on make/model)this resistance is "damped" providing a "smoothed " voltage to meter. since unplugging meter allows empy reading, would suspect sender or wiring to meter. I'd start by unpluging sender at tank & go from there.Luck G

thanks g, I'll check wiring to the meter. What does a sender look like? Sounds like it plugs in directly at the tank? I wonder if KZ Enterprises sells stuff like this? I will take a closer look..

I see the sender units come up on EBay every once in a while. Just keep an eye out for them there.

thanks for help on this.

How are these sender units user serviceable/replaceable from INSIDE the gas tank? Do they actually just unplug or unscrew from the bottom of the tank? It seems like you might need to purchase another gas tank to have another chance at a working sender..If I were able to find one, what would be a reasonable price to pay for this part? My guess is it'd probably have to be used, right?

I have tested the wiring around the sender and all appears good. I found a new fuel sender for sale. It has no picture but has an OEM part number for cross-reference. I went to bikebandit.com to look up the sender assembly schematics on the fuel tank, but they didn't have a picture/part number. Does anyone know whether the sender assembly includes black wiring on one end that has a white connector on the tip? I can't tell if the sender is that whole, complete assembly, or just the float inside the tank. This is good to know, since I'm not sure if buying this $100 "sender" would actually include everything I need (including wiring) to get the fuel gauge working again.

No eBay APP ID and/or Cert ID defined in Kunena configuration$100 sounds about right for a whole new sending unit. It *should* come with everything you need to connect to the gauge, float, unit, wires, possibly a gasket. I would check the return policy for the site or try to contact their CS before ordering if you're afraid of getting burned.



probably a minimum that you would receive in that pic

First unplug the sending unit and see if the gauge drops to empty. If it still shows full than it is the gauge and not the sending unit. I have fixed my sending units plenty of times. Sometimes they are just loaded up with goop and sometimes the reostat wire is broken.