Guys looking for some help.
2010 Ultra- My gas gauge has always been rock solid and accurate...I was riding this week and filled up my tank. After the fill up whenever I accelerated or braked the gas gauge would bounce wildly up and down like crazy. It is all over the place unless I am sitting idling or parked.
Any advice on if this is the sending unit or float, and are the built together as one unit? (I don't think it is the gauge as it reads ok when stopped.).

Thanks all,
Dave

 

it is all one unit.

I've never watched mine when stopping or starting...

you can see an illustration here:

http://partsfinder.onlinemicrofiche....m_oem/hdmc.asp

 

these bikes have gas gauges?

seriously, the gauges have been known for being wildly inaccurate. as a result, that and having a sportster for a few years, i don't use the gauge for anything but to plug a hole in the fairing. i go by the odometer.

i say this only so after looking at your sending unit, etc. if it looks like its gonna cost a pile of cash to repair/replace, i wouldn't..... i can think of better things to spend my money on.

 

When I had Sporsters I went by the odometer all the time. Now with my King I use the gauge all the time, I would be lost with out it now.
I would look in to how much a new sending unit would cost.

 

Thanks...This helps. 79 bucks...not as bad as I thought.

I will order one this week and replace it. Might as well do the filter while I am in there.

 

I suspect there is a "dampening circuit" somewhere in the system which averages out the float going up and down rapidly as the fuel sloshes and this is what has failed. I have absolutely no idea if it is in the master computer, in the float assembly or contained within the gas gauge. With you, I would have hoped for someone knowledgeable in the system to help identify the actual failure. Does the needle "jump" to the current level indication when the power is turned on? Mine moves very slowly and doesn't wiggle when under way.

If the "damper" is in the gauge, your planned purchase is the answer, if it is somewhere else, you may be wasting your $79.

 

I was told that by the dealer I bought my bike from - actually, my gas guage is right on the money.

I just wish it stayed "Full" for longer...

 

Is the bike not under warranty?

 

I've owned several HD's with fuel gauges and even though they haven't all been 100% accurate, they've all been consistent. That is they read the same way every time.
When my '95 EGC says 1/4 tank left, it means it - start thinking about fuel. But my '06 SG will actually have about 1/4 tank left when the gauge reads 1/2. I just had to learn each bike.

 

Mine used to be rock solid also then one day I added some octane booster to the tank and then filled it up. The gauge started acting like you described very soon after. Maybe that is the culprit??