Fuel gauge anomaly

This morning, decided to take my 08 out to run some errands. Had been sitting in garage for approx a month. Started up quickly as per usual. Happened to look down at the gauges and noticed the fuel gauge flashing on the last possible bar as if the tank was just about empty. Garage floor is clean concrete and any fuel leak would have been obvious. Garage and of course the gas cap is locked so that ruled out any possible siphoning. After approx 1 minute of idling, the gauge gained another bar, another 30 seconds and yet another bar appeared. At that point I concluded that for some unknown reason, the gauge was self-correcting. I proceeded to drive off and within 3 miles, the tank indicated full, as it should have. Since I keep the tank full as a matter of practice, I was fully expecting to see a full indication after start-up. Each start the rest of the morning resulted in normal operation. Just wanted to share this experience as I had never read of a like problem on this or any other forum.

Try some Techron fuel system cleaner. It can help clean the sending unit and a few other things..
I use it at least once a year to clean some carbon from engine and clean injectors.

Auto parts stores sell it. I buy 1qt bottle 1 oz per. gallon mix ratio. It can be bought in smaller bottles but is more concentrated just use a little less.  Run 2 complete tank fulls and see if problem continues.

Thanks Mech 1. Can you confirm the spelling of Tecnron?
Also, will Seafoam work just as well, I know I can get that.

Sorry Techron. Chevron Techron. Seafoam if different but also cleans injectors and carbon .

Gonna chime in here...

Seafoam is probably the best choice to clean-up the non-combustion side of the fuel system, as it's a solvent and can dissolve deposits.

On the other hand, Techron has a solvent base, but not as aggressive as Seafoam's, but it has a detergent to clean combustion products from the valves and pistons.
Another very good  detergent additive is Gumout's Regane.

These measures are mostly unnecessary if You use a Top Tier fuel like Shell, BP, Chevron etc.
Top Tier fuels generally exceed requirements for detergency.

I just have to say it never fails to amuse me the amount of posts there are about this Seafoam stuff. It seems to be tipped into fuel tanks for all manner of reasons as if it was an automotive aspirin, energy drink, indigestion remedy, or placebo.

Meanwhile on our side of the Pond, Seafoam would probably be the name of a race horse.  

I recommended Techron because their website says it can clean the sulfur from a fuel sending unit. restoring its operation.

Infrequent use and Ethanol fuel tend to gum things up.

Does UK add Ethanol to gas? We run 10% over here and they... FED wants to add more.
Big stink about that. Will void many Warranties but pumps are clearly marked.

As far as I know the UK doesn't ram E10 down everyone's nozzle, so you won't have the same fuel system issues as we do.
I don't have problems because I ride a lot, so I fill-up every day.
I also use Shell and Exon fuel.

Some people use poor quality gas and because they ride very little, the fuel separates and absorbs moisture. This will cause tank, fuel pump and injector deposits.

IF you use GOOD gas, and, ride often, AND your machine is running well, you will not need additives.
The additives are included in top tier fuels.

No we haven't had E10 fuel rammed down our nozzles, but I have used E10 fuel over in Germany a couple of times and it isn't too popular over there either.  On occasion I have had what you'd call stale fuel in my tank for a long period of time, e.g. I couldn't ride for over two months after my stroke, and there was a similar period of time when family events and holidays prevented me riding and I had to put the Silver Wing in storage.

Nothing drastic happened, the Silver Wing started first press of the button and all I had to do was go out and clock up some miles to go on Reserve and then fill up with fresh petrol. Winter just means a change of routine, it's a maxi scooter not a pet hamster and doesn't need to go into hibernation for months on end.

In my seven years with this Silver Wing, I've never used any fuel injector cleaner, fuel stabiliser, or any other fuel supplement. I do have a pack of mini bottles of Redex that I bought a few years ago, and I've yet to use any of them

I wouldn't know about GOOD gas, it's all pretty much the same to me and for the prices we have to pay for a litre of Unleaded I have no problem using cheaper supermarket brand fuels. If I was running low with the last bar on the fuel gauge flashing I wouldn't be too fussy where I filled up.

As all our petroleum has to refined to a specific standard and comes to the pumps from the same refineries and fuel depots. It's only the additives package that is added to the different brands that changes.

I think that all fuel in the U K has a percentage of biofuel of some sort in it but not sure how much or what it is . All our fuel conforms to a minimum standard, it's only the additives and price that vary.

Meldrew wrote:

I just have to say it never fails to amuse me the amount of posts there are about this Seafoam stuff. It seems to be tipped into fuel tanks for all manner of reasons as if it was an automotive aspirin, energy drink, indigestion remedy, or placebo.

Meanwhile on our side of the Pond, Seafoam would probably be the name of a race horse.  

I think it cures dropsy too.

It was developed in 50s as a fuel system cleaner for marine engines run too cold (short trips, improper/failed thermostat, etc.), run with contaminated fuel, or improperly stored over (mostly over the winter)--that's where the "sea" part comes from. It is mostly kerosene (paraffin for those on t'other side of the pond), with small amounts of "cleaners"--light end aromatic solvents that any pump gasoline in the US has anyway.

In Seafoam they are mostly to make it not smell like kerosene.

I have never used it, in over 60 years of owning powered boats and vehicles, largely because I have never allowed an engine to run too cold, , run on contaminated fuel, or be improperly stored for months.

It's use is not recommended by any manufacturer of which I am aware; in fact most manufacturers specifically state such fuel and oil additives should NOT be used, often with a "may void your warranty" warning (though their proving that the snake oil fouled something up would be unlikely)...

Thanks to Mech 1  twa and Sidewinder Pilot for the helpful info and suggestions on Seafoam.
I did add it to the fuel at the dosage recommended on the can, and the gauge is now working normally.
I do appreciate you sharing your knowledge and experience.

I use Seafoam in my vehicles once in a while but use it all the time in my gas can for my snowblower and lawn mowers. Unleaded gas can go bad within a year or two from what I've heard. Sometimes the gas in the can will be 3-4 years old before I have to refill it. I've never had any problems with my equipment using Seafoam in the gas. I also never drain the tank like some say to do and my equipment starts on the first or second pull all the time. I also dump a can in my pickup 2-3 times a year just for the heck of it. And about 1/4 can into the SWing once at the beginning of the summer before I fill it up.

Dale N. wrote:

I use Seafoam in my vehicles once in a while but use it all the time in my gas can for my snowblower and lawn mowers. Unleaded gas can go bad within a year or two from what I've heard. Sometimes the gas in the can will be 3-4 years old before I have to refill it. I've never had any problems with my equipment using Seafoam in the gas. I also never drain the tank like some say to do and my equipment starts on the first or second pull all the time. I also dump a can in my pickup 2-3 times a year just for the heck of it. And about 1/4 can into the SWing once at the beginning of the summer before I fill it up.

Gee, Dale, you could dump that Seafoamed fuel from your spare can into your truck rather than allowing it to sit around degrading for 2-3 years. You'd be much less likely to contaminate a 15 gallon tank in your truck than you would the 4 gallon tank in your scoot. 

Anyway you would be able to have a fesh supply of spare fuel on hand if you "rotate your stock"

Tim

Hi Tim,
I don't use the gas from the can in my SWing. It's only for my lawn mowers and snowblower. I've never had a problem with it degrading with the Seafoam in it. I'll dump maybe 1/4 can of Seafoam in the SWing once at the beginning of the  season when I fill the first tank. My pickup might get a can of Seafoam a couple of times during the year just to keep everything clean.

I use STA-BIL fuel additive in my equipment that don't get used regularly. I use it in my boat, lawnmower and weed whacker gas cans. I didn't know Sea Foam works the same way.

I think they both work in the same sort of way. It's 6 of one Half Dozen of the other.

StaBil also makes a product for the 10% fuel that absorbs moisture. Just had to have my lawn mower cleaned up due to water in the fuel. Mech sold me a bottle of this product and you only use 2oz per gal to clean up any water. The ethonal will absorb water if left to long.

StaBil is a good product many different products that work.

The only thing that will remove water is more alcohol. Best to fill tank and add StaBil at end of season.
Things will start in spring no problems then run fresh fuel after that.

Probably a dirty or stuck "potentiometer" on the fuel sending guage.

I always remove fuel for long term storage and either drain fuel sediment bowl or run engine till it quits. Never used additives. Fresh fuel on first use and sometimes i use hitest if i think engine is running a bit rough. Either full or empty tanks especially on a boat. I experienced a fuel fugus in the boat which was costly. Pros said seafoam or stabil would not have helped.
Small engines have have always started right away.

Jury seems to be out on stabil, however i have used it in the past on random occasions.

I use a trickle charger on the scooter and leave tank full. Never fails to start immediately after six months ( for past six yrs). Just t urned 40k kms this week...... Service manual least used... Should be able to sell "as new"

Meldrew wrote:

I just have to say it never fails to amuse me the amount of posts there are about this Seafoam stuff. It seems to be tipped into fuel tanks for all manner of reasons as if it was an automotive aspirin, energy drink, indigestion remedy, or placebo.

Meanwhile on our side of the Pond, Seafoam would probably be the name of a race horse.  

Seafoam was formulated in the 50s for cleaning out marine engines that ran perpetually cold and/or were improperly stored over the winter months--that's the "sea" part...

It is mostly naptha and other light-end petroleum solvents, however it also contains 15% to 20% isopropanol (rubbing alcohol)--the alcohol is bad for many composite materials used in the fuel system, where is can cause softening and swelling of seals/hoses/and the like. There is no reason to use Seafoamin any properly maintained engine or fuel system; in fact most manufacturers specifically recommend against using such additives.

The electronic fuel gauge circuitry is highly damped to prevent the indicator from swinging about wildly over bumps, when turning, etc. I suspect what the OP observed was those damping circuits "waking up" (capacitors charging,, after being switched off for an extended time.