Fuel Gauge Sticking At Three Bars

[Andrew Shadow]

When I stored my 2009 ST1300 last fall the fuel gauge was working normally. Since I put it back on the road this spring the fuel gauge has been acting up. It reads full (8 bars) after every fill-up. It reads completely normal and decreases the number of bars all the way down to three bars. It then stays "stuck" at three bars for a very long time. Then suddenly it will go from three bars directly to one bar flashing and the estimated remaining range. I never see two bars anymore. Can anyone tell me what the problem is?

Thanks.

 

[v8-7]

Probably the upper sender hanging up .
If you can work it through the entire range, it will most likely free it up.

 

[st1300r]

Upper sensor should be 1-6 ohms full and 213-219 ohms empty and no drop outs or radical changes in its range of motion.

 

[Andrew Shadow]

work it through the entire range

When you say "work it through the entire range" I am assuming that you mean physically move the float arm through its full travel. Can this be done through the fuel filler or do I need to go in to the tank to do so? It has cycled through several full cycles from full to empty on its own by burning through several tanks of gas while riding but it is still hanging up.

 

[v8-7]

Take the resistance measurements ,as Carl mentioned, and see if you can physically lower the sender to get the ~215 ohms

I would take a coat hanger and try to work it up and down...gently..while looking at the ohmmeter

If that doesn't work, I would empty and pull the tank off , then pull the sender off and work it and measure the resistance .

 

[Tom Mac 04a]

There are a couple of old treads re this ;
https://www.st-owners.com/forums/showthread.php?25209-Bad-Upper-Fuel-Sender

https://www.st-owners.com/forums/showthread.php?33346-Fuel-Gauge-3-Bars-to-1-Bar-Flashing

https://www.st-owners.com/forums/showthread.php?109753-Wildly-fluctuating-fuel-gauge

https://www.st-owners.com/forums/archive/index.php/t-82984.html

Also happen to me.... My fix was to add seafoam for the next few tanks... it must have cleaned the crud off of something.
Also remember there was some problems with people putting siphon hoses in tank ( left or right ? ) and bending the sending arm throwing off reading

 

[Blrfl]

Can this be done through the fuel filler or do I need to go in to the tank to do so? It has cycled through several full cycles from full to empty on its own by burning through several tanks of gas while riding but it is still hanging up.

Sounds like your sender has probably had it. Not a frequent occurrence, but not anything we haven't seen before. Unless you stuck something in the tank and damaged the arm, odds are very good it's an electrical failure.

You should still be able to run the fuel down to one blinking bar, after which you can raise the upper tank and remove the sender from the underside, do the diagnostic and re-install it.

--Mark

 

[Andrew Shadow]

I have never stuck anything in the tank so everything is undisturbed. Prior to asking this question here I had already dumped some Seafoam in the tank so I will wait and see if that has any effect before I proceed with any further diagnostics. Funny how things can go a wry while the bike is just sitting there hibernating- winter gremlins I guess.

Thank you for the replies.

 

[cornSTalk]

When I stored my 2009 ST1300 last fall the fuel gauge was working normally. Since I put it back on the road this spring the fuel gauge has been acting up. It reads full (8 bars) after every fill-up. It reads completely normal and decreases the number of bars all the way down to three bars. It then stays "stuck" at three bars for a very long time. Then suddenly it will go from three bars directly to one bar flashing and the estimated remaining range. I never see two bars anymore. Can anyone tell me what the problem is?

Thanks.

Was wondering how much fuel you had in the tank when it was stored. I have had similar experiences twice. The first was in 2013 after the fuel gauge was working perfectly in 2012 and sat over winter. Upon turning on the key I would have all 8 bars flashing all the time, no matter how much fuel was in the tank. After several rides the gauge quit flashing but wasn't accurate. Then every so often all 8 would flash again. All summer it went on like this but got progressively better. Then in 2014 it worked perfect all summer. Then I parked it this past winter with no fuel in the main tank so I could do maintenance on it during the winter. Upon start up several months later it was acting the same as 2 years ago. 8 bars flashing. I thought maybe it was because of no fuel in the tank. Can't remember how much was in it two years ago. So far this season the flashing has stopped but not very accurate. Time will tell if it corrects itself but I too would like to know what is the cause.

 

[Blrfl]

All bars flashing is what you get when the dash thinks the sender is disconnected. That means you either have a connection problem or the sender has failed and no longer makes a complete circuit.

--Mark

 

[Andrew Shadow]

Was wondering how much fuel you had in the tank when it was stored.

Unfortunately it sat for a couple of months with only 3 bars of fuel- or at least that it is what it displayed. I intentionally left it low because I was planning to remove the upper tank for some farkeling. Due to the brutal winter we had it never happened. Once I determined I was not going to get to it I filled the tank from a gas can to have it full for the remainder of the winter. All that to say that it was pretty much the same scenario as yourself.

 

[ST1300 Alicia]

You guy's and your fuel gauge problems. That's why I ride a Beemer. They replace the fuel sensing strip three or four times under warranty and then you just give up and use the Odometer. Works great. No gauge No problem.

 

[Tor]

That's why I ride a Beemer.

:bow1: :

 

[lectricmojo]

You guy's and your fuel gauge problems. That's why I ride a Beemer. They replace the fuel sensing strip three or four times under warranty and then you just give up and use the Odometer. Works great. No gauge No problem.

I know, right. Mine sticks on the three bars for a while, then... 1 flasher , at least that works, time to get gas...
but mainly I just use my odometer too (and fill it back up before it gets to the flashy... (that's usually 200 miles or so)

 

[Andrew Shadow]

I just came across this thread while looking for something else and thought that I should provide the resolution that worked for me for the benefit of anyone else who has this same problem and comes across this thread.

At the time I mostly only rode on weekends. I dumped in double the amount of SeaFoam (full bottle) with a full tank of gas and let it sit for a week. Then I burned out that gas and did the same thing again for the next week. It had a high concentration of SeaFoam in the gas for a full two weeks. I burned out that gas and put SeaFoam in at the regular concentration for the next two tanks. Total of three bottles of SeaFoam. So, high concentration of SeaFoam over the course of two weeks.

This must have dissolved some varnish or other contaminants off of the upper sending unit allowing the electrical connection to be reestablished. I did not do anything else and the gauge started working properly again. I have never had any trouble with the gauge since.

 

[Honda-st-team]

Great Information

 

[klaproth]

This must have dissolved some varnish or other contaminants off of the upper sending unit allowing the electrical connection to be reestablished. I did not do anything else and the gauge started working properly again. I have never had any trouble with the gauge since.

A while back, I had this same issue- stuck at 3 or 4 bars, then it would suddenly go to flashing 1 bar. I took out the sending unit, while replacing the large fuel tube at the back of the tank. I tested it, and got spotty resistance readings it towards the "empty" part of the range, so I cleaned off the copper conductive pads on the sender with an abrasive eraser, just so they were shiny, and tested again....worked like a charm. No problems since then. I like Andrew's solution better though...less hassle.

 

[Rob20111]

As with all my bikes stored for 6 months of the year every year, always with a full tank of premium and the recommended amount of fuel stabilizer.
No problems.

 

[Andrew Shadow]

As with all my bikes stored for 6 months of the year every year, always with a full tank of premium and the recommended amount of fuel stabilizer.
No problems.

I am of the opinion that the best option is to burn off as much of the fuel in the tank that contains ethanol as possible. Then fill the tank with ethanol-free fuel if possible for storage. If this is not possible don't worry about it to much, it is more important that the tank be full in my opinion.

Prior to ethanol fuels, I never used any additives and never had any problem with fuel during winter storage. I started using stabilizers because of what I heard about ethanol. Then I either got lazy or would forget and no stabilizer was added. I have never seen any difference because I hadn't put in stabilizer, so I don't bother any more.

Check out Ryan F9's take on fuel stabilizers. After seeing his report it sounds like these additives might do more harm then good.