K12 Fuel gauge stuck

I have a '04 K12GT that has run flawlessly. After being off the bike for about the last three weeks with snow, travel, etc I have had the bike sputter and die on me two times. First time it died gauge said a little over a 1/4 tank. I thought it was water in the fuel, added some stabil and fresh gas and started right up. Then it happened again last nite, sputtered like its out of fuel, but gauge still says 1/4 tank. Added gas, ran fine. SO, I have run out of gas twice with a previously very accurate gauge saying 1/4 tank.

I'm thinking its the fuel sensor/sending unit. I'm going to drain the tank and pull the sensor this weekend to check for crud, water, etc that might be messing things up. Hope I'll get lucky that there is something jamming the float. But before I do, was wondering if anybody has had this problem? Wondering if this is something physically messing up the float/spring or if its an electrical problem. I thought I had seen a previous post saying something about voltage issues in the sensor/sending unit but cant find the post. Any help is appreciated!

Thanks, Bob

Check your fuel vent lines..could be pinched..very common problem if you had your tank off recently. What happens vaccum builds up and kills the engine..not only that it deforms your tank and squeezes and deforms the fuel gauge sending unit tube inside your tank, possible reason why your seeing 1/4 tank when in accuality your empty.. been there done that.. If that is the issue the unit is not servicable but I did fix it by taking it apart and pushing out the deformity by pushing a socket that fits inside the tube.

Thanks Clay,

I haven't had the tank off since last July, but maybe the vent tubes have gotten clogged? (I did hear some hissing when I opened the gascap the other day). I'll definitely check them when I've gotten things apart.

For the deformity in the sending unit tube was the float deformed within the tube, or was it the tube itself that was deformed?

B

Yep..definitly sounds like a clogged/pinched fuel vent line..if you hear "hissing" when opening your gas cap. What probably happened is the tank deformed to a point where the fuel sending unit outer tube is bent inward preventing the inside float from rising/falling.

Take the unit out of the gas tank and you'll probably see the deformity. I took mine apart..not very hard.. and find a socket that will just fit inside of the tube and push out the deformity.

Don't forget to find that clogged/pinched fuel vent line...

While you guys have your fuel gauge thinking caps on, I have a '05 K1200S that the fuel gauge reads empty all the time. It worked when I first got it (used) but shortly after would not register any fuel. Could it be a similar answer to the previous model? Or is this a completely differant type of gauge?

I basically keep track of mileage, and don't run it down too far, so it hasn't been a problem, but I'm getting tired of the low fuel warning light blinking at me..........

Thanks!

john1691 said:

While you guys have your fuel gauge thinking caps on, I have a '05 K1200S that the fuel gauge reads empty all the time. It worked when I first got it (used) but shortly after would not register any fuel. Could it be a similar answer to the previous model? Or is this a completely differant type of gauge?

I basically keep track of mileage, and don't run it down too far, so it hasn't been a problem, but I'm getting tired of the low fuel warning light blinking at me..........

Thanks!

Click to expand...

Yours uses a fuel strip. No float or etc. They go out sometimes and need to be replaced. Viki and I have had three of them go out on three different K12S bikes.

Is that something I can do myself, or does it require some goofy dealer only tool?

john1691 said:

Is that something I can do myself, or does it require some goofy dealer only tool?

Click to expand...

There are two issues, one is a large tool to remove the gas pump assembly ring (you could carefully use a drift and hammer), and the other is the calibration of the new (dry) strip requirement. It's probably about an hour for an experienced shop and the reinstall of the pump, etc. has to be done with some care as to a big gasket in place, etc. It's not that you can't do it, but it would be good to watch it once. Of course the calibration is pretty much dealer only with the GT-1 computer. I don't know what exactly the error would be without it. It may be tolerable.

Thanks Jack, guess I'll keep going as I have been until I decide I want to spend the money at the dealer.

I drained the tank this weekend, no kinks in the vent hoses, but blew some crud out of them with the air compressor and now there is no vacuum when I open the tank.

I pulled the sensor and did a repair as Clay had. It seemed to go okay, although there is still a bit of a ripple in the sensor tube. Took a short ride and so far the gauge seems to be working, but I will go on a longer ride and burn through a couple of tanks before I am sure.

Just in case the sensor is toast and I have to replace it does anyone know if the need for a computer to calibrate also applies to the fuel sensor on the '04 K12?

Clymer manual says calibration is needed but does not say how. I dont see anything to adjust on the sensor itself so I guess if calibration is needed maybe its at the computer end of things.

When a new sensor is installed, it should be calibrated as to reserve with one gallon of fuel in the tank. This is done with the diagnostic computer at the dealer. Again, I don't know how tolerable the error would be with a new sensor and no cal. Might be just fine plus or minus a quarter gallon or so.